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Python | I initially had some code that aggregated results into a list . When I refactored this code to use a list comphrehension , I am getting unexpected results : If I run this code I get this output : Why do I get different results for third huh ( ) function ? | import asyncio @ asyncio.coroutinedef coro ( ) : return `` foo '' # Writing the code without a list comp works , # even with an asyncio.sleep ( 0.1 ) . @ asyncio.coroutinedef good ( ) : yield from asyncio.sleep ( 0.1 ) result = [ ] for i in range ( 3 ) : current = yield from coro ( ) result.append ( current ) return re... | Why am I getting different results when using a list comprehension with coroutines with asyncio ? |
Python | I am working on this python notebook in Google Collab : https : //github.com/AllenDowney/ModSimPy/blob/master/notebooks/chap01.ipynbI had to change the configuration line because the one stated in the original was erroring out : However , I think the original statement was meant to show values of assignments ( if I 'm ... | # Configure Jupyter to display the assigned value after an assignment # Line commented below because errors out # % config InteractiveShell.ast_node_interactivity='last_expr_or_assign ' # Edit solution given below % config InteractiveShell.ast_node_interactivity='last_expr ' meter = UNITS.metersecond = UNITS.seconda = ... | Google Collab How to show value of assignments ? |
Python | Here 's a small example : ( In both cases the file has -*- coding : utf-8 -*- ) In Python 2 : Whereas , in Python 3 : The above behaviour is 100 % perfect , but switching to Python 3 is currently not an option . What 's the best way to replicate 3 's results in 2 , that works in both narrow and wide Python builds ? The... | reg = ur '' ( ( ? P < initial > [ +\- ] ) ( ? P < rest > .+ ? ) ) $ '' re.match ( reg , u '' hello '' ) .groupdict ( ) # = > { u'initial ' : u'\ud83d ' , u'rest ' : u'\udc4dhello ' } # unicode why must you do this re.match ( reg , `` hello '' ) .groupdict ( ) # = > { 'initial ' : `` , 'rest ' : 'hello ' } | Treat an emoji as one character in a regex |
Python | I just came across something that was quite strange . Why does it raise TypeError and yet change the list inside the tuple ? | > > > t = ( [ ] , ) > > > t [ 0 ] .append ( 'hello ' ) > > > t ( [ 'hello ' ] , ) > > > t [ 0 ] += [ 'world ' ] Traceback ( most recent call last ) : File `` < stdin > '' , line 1 , in < module > TypeError : 'tuple ' object does not support item assignment > > > t ( [ 'hello ' , 'world ' ] , ) | Why does += of a list within a Python tuple raise TypeError but modify the list anyway ? |
Python | I want to obtain the true value of the operating system 's argv [ 0 ] in a Python program . Python 's sys.argv [ 0 ] is not this value : it is the name of the Python script being executed ( with some exceptions ) . What I want is a foo.py that will print `` somestring '' when executed asThe trivial programwill print ``... | exec -a `` somestring '' python foo.py # ! /usr/bin/env pythonimport sysprint sys.argv [ 0 ] | How can you obtain the OS 's argv [ 0 ] ( not sys.argv [ 0 ] ) in Python ? |
Python | I want to scatter plot the first two columns of the following pandas.DataFrame , with the third column as color values . If I try : I get And the X-axis disappears.I tried ax.set_axis_on ( ) and ax.axis ( 'on ' ) to no avail . | > > > df = pd.DataFrame ( { ' a ' : { '1128 ' : -2 , '1129 ' : 0 , '1146 ' : -4 , '1142 ' : -3 , '1154 ' : -2 , '1130 ' : -1 , '1125 ' : -1 , '1126 ' : -2 , '1127 ' : -5 , '1135 ' : -2 } , ' c ' : { '1128 ' : 5300 , '1129 ' : 6500 , '1146 ' : 8900 , '1142 ' : 8900 , '1154 ' : 9000 , '1130 ' : 5600 , '1125 ' : 9400 , '1... | Scatter plot with colormap makes X-axis disappear |
Python | I try to understand how the logging module really works . The following code does n't react like I expected.It just print out this to the console.But why ? Should n't there be info and debug , too ? Why not ? The question is not how to fix this . I know about handlers and things like that . I just try to understand how... | # ! /usr/bin/env python3import loggingl = logging.getLogger ( ) l.setLevel ( logging.DEBUG ) print ( 'enabled for DEBUG : { } '.format ( l.isEnabledFor ( logging.DEBUG ) ) ) l.debug ( 'debug ' ) l.info ( 'info ' ) l.warning ( 'warning ' ) l.error ( 'error ' ) l.critical ( 'critical ' ) warningerrorcritical | Why does logging.setLevel ( ) has no effect here with Python ? |
Python | On most types/classes in Python , I can call .mro ( ) without arguments . But not on type and its descendants : It appears I can get what I want with type ( type ( 4 ) ) .mro ( type ( 4 ) ) , but why ca n't I call mro ( ) directly as I do elsewhere ? | In [ 32 ] : type ( 4 ) .mro ( ) Out [ 32 ] : [ int , object ] In [ 33 ] : type ( type ( 4 ) ) .mro ( ) -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -TypeError Traceback ( most recent call last ) < ipython-input-33-48a6f7fcd2fe > in < module > ( ) -- -- >... | Why does .mro ( ) on a metaclass have a different signature ? ` descriptor 'mro ' of 'type ' object needs an argument ` |
Python | I am looking for a simple way to visualize some of my data in numpy , and I discovered the mlabwrap package which looks really promising . I am trying to create a simple plot with the ability to be updated as the data changes . Here is the matlab code that I am trying to duplicateto pythonHowever , the second to last c... | > > h = plot ( [ 1,2,3 ] , [ 1,2,3 ] , '-o ' ) ; > > set ( h , 'XData ' , [ 0,0,0 ] ) ; > > drawnow ( ) ; > > from mlabwrap import mlab > > h = mlab.plot ( [ 1,2,3 ] , [ 1,2,3 ] , '-o ' ) > > mlab.set ( h , 'XData ' , [ 0,0,0 ] ) > > mlab.drawnow ( ) ; error : One or more output arguments not assigned during call to ``... | numpy to matlab interface with mlabwrap |
Python | I count the occurrences of items in a list usingWhich gives me this : I want to separate the parts of the list items ( 3 and 1575 for example ) and store them in a list of lists . How do I do this ? | timesCrime = Counter ( districts ) Counter ( { 3 : 1575 , 2 : 1462 , 6 : 1359 , 4 : 1161 , 5 : 1159 , 1 : 868 } ) | Split the result of 'counter ' |
Python | I have several files across several folders like this : How can I extract all the documents into a single folder appending the folder name for each moved document : I tried to extract them with : UPDATEAlso , I tried to : The above gave me the path of each file . However , I do not understand how to rename and move the... | dir├── 0│ ├── 103425.xml│ ├── 105340.xml│ ├── 109454.xml││── 1247│ └── doc.xml├── 14568│ └── doc.xml├── 1659│ └── doc.xml├── 10450│ └── doc.xml├── 10351│ └── doc.xml new_dir├── 0_103425.xml├── 0_105340.xml├── 0_109454.xml├── 1247_doc.xml├── 14568_doc.xml├── 1659_doc.xml├── 10450_doc.xml├── 10351_doc.xml import osfor pa... | How to move and rename documents placed in several nested folders into a new single folder with python ? |
Python | Is there a way to connect to an RFC2217 networked serial port with Twisted Python ? Pyserial seems to support it via the serial.serial_for_url ( `` rfc2217 : // ... '' ) function . And they indicate that twisted uses pyserial for managing serial connections , however twisted.internet.serialport.SerialPort seems to expe... | socat PTY , link=/dev/myport TCP:192.168.1.222:9001 try : s = serial.serial_for_url ( ... ) except AttributeError : s = serial.Serial ( ... ) | Use RFC2217 network serial ports with Twisted Python ? |
Python | I have WSGI middleware that needs to capture the HTTP status ( e.g . 200 OK ) that inner layers of middleware return by calling start_response . Currently I 'm doing the following , but abusing a list does n't seem to be the “ right ” solution to me : The reason for the list abuse is that I can not assign a new value t... | class TransactionalMiddlewareInterface ( object ) : def __init__ ( self , application , **config ) : self.application = application self.config = config def __call__ ( self , environ , start_response ) : status = [ ] def local_start ( stat_str , headers= [ ] ) : status.append ( int ( stat_str.split ( ' ' ) [ 0 ] ) ) re... | What is the appropriate way to intercept WSGI start_response ? |
Python | So , I recently got into programming in python and decided to make a simple code which ran some simple maths e.g calculating the missing angle in a triangle and other simple things like that . After I made the program and a few others , I thought that maybe other people I know could use this so I decided to try and mak... | a = int ( input ( `` What 's one of the angles ? `` ) ) b = int ( input ( `` What 's the other angle in the triangle ? `` ) ) c = ( a + b ) d = 180f = int ( 180 - c ) print ( f ) | A simple looping command In Python |
Python | For educational purposes , I 'm trying to scrape this page gradually with Python and lxml , starting with movie names.From what I 've read so far from the Python docs on lxml and the W3Schools on XPath , this code should yield me all movie titles in a list : Basically , it should give me every h3 element anywhere in th... | from lxml import htmlimport requestspage = requests.get ( 'http : //www.rottentomatoes.com/browse/dvd-top-rentals/ ' ) tree = html.fromstring ( page.text ) movies = tree.xpath ( '//h3 [ @ class= '' movieTitle '' ] /text ( ) ' ) print movies movies = tree.xpath ( '//h3 [ @ class ] /text ( ) ' ) print movies [ 'From RT U... | How to scrape this webpage with Python and lxml ? empty list returned |
Python | As a `` sanity check '' I tried two ways to use transfer learning that I expected to behave the same , if not in running time than at least in the results.The first method was use of bottleneck features ( as explained here https : //blog.keras.io/building-powerful-image-classification-models-using-very-little-data.html... | Epoch 1/5016/16 [ ============================== ] - 0s - loss : 1.3095 - acc : 0.4375 - val_loss : 0.4533 - val_acc : 0.7500Epoch 2/5016/16 [ ============================== ] - 0s - loss : 0.3555 - acc : 0.8125 - val_loss : 0.2305 - val_acc : 1.0000Epoch 3/5016/16 [ ============================== ] - 0s - loss : 0.136... | Training a dense layer from bottleneck features vs. freezing all layers but the last - should be the same , but they behave differently |
Python | I want to detect features inside an image ( retina scan ) . The image consists of a retina scan inside a rectangular box with black background . I am working with Python 3.6 , and I am using Canny Edge Detection to detect features inside the image . I understand that the algorithm for canny edge detection uses edge gra... | import cv2import matplotlib.pyplot as pltfrom matplotlib.pyplot import imread as imreadplt.figure ( 1 ) img_DR = cv2.imread ( 'img.tif',0 ) edges_DR = cv2.Canny ( img_DR,20,40 ) plt.subplot ( 121 ) , plt.imshow ( img_DR ) plt.title ( 'Original Image ' ) , plt.xticks ( [ ] ) , plt.yticks ( [ ] ) plt.subplot ( 122 ) , pl... | Obtain features inside image and remove boundary |
Python | As you know I can do df [ df.column.isin ( set ) ] to get the part of the DataFrame where the column value is in that set . But now my source set is dependent on the value of column1 . How do I make the function lookup a dictionary for the source set on the go , as it filters the dataframe ? let 's say i have and my df... | dict1= { ' a ' : [ 1,2,3 ] , ' b ' : [ 1,2 ] , ' c ' : [ 4,5,6 ] } column1 column2a 4b 2c 6 column1 column2b 2c 6 | How to use series.isin with different sets for different values ? |
Python | I 'm looking for a way to element-wise multiply two 2d arrays of shape ( a , b ) and ( b , c ) , respectively . Over the ' b ' axis , which the two arrays have in common.For instance , an example of what I 'd like to broadcast ( vectorize ) is : Does anyone know what to do here ? Is there a better way ? | import numpy as np # some dummy dataA = np.empty ( ( 2 , 3 ) ) B = np.empty ( ( 3 , 4 ) ) # naive implementationC = np.vstack ( np.kron ( A [ : , i ] , B [ i , : ] ) for i in [ 0 , 1 , 2 ] ) # this should give ( 3 , 2 , 4 ) C.shape | numpy : broadcast multiplication over one common axis of two 2d arrays |
Python | I 'm expecting to get set ( [ nan,0,1 ] ) but I get set ( [ nan , 0.0 , nan , 1.0 ] ) : | > > > import numpy as np > > > import pandas as pd > > > l= [ np.nan,0,1 , np.nan ] > > > set ( pd.Series ( l ) ) set ( [ nan , 0.0 , nan , 1.0 ] ) > > > set ( pd.Series ( l ) .tolist ( ) ) set ( [ nan , 0.0 , nan , 1.0 ] ) > > > set ( l ) set ( [ nan , 0 , 1 ] ) | Reducing pandas series with multiple nan values to a set gives multiple nan values |
Python | I 'm working on a deep learning project in which we use RNN . I want to encode the data before it 's fed to the network . Input is Arabic verses , which have diacritics that are treated as separate characters in Python . I should encode/represent the character with the character following it with a number if the charac... | map ( lambda ch , next_ch : encode ( ch + next_ch ) if is_diacritic ( next_ch ) else encode ( ch ) , verse ) XXA ) L_I ! I % M < LLL > MMQ*Q [ ' X ' , ' X ' , ' A ) ' , 'L_ ' , ' I ! ' , ' I % ' , 'M < ' , ' L ' , ' L ' , ' L > ' , 'M ' , 'M ' , ' Q* ' , ' Q ' ] X+Y_XX+YYYY_ [ ' X ' , ' X+ ' , 'X_ ' , ' Y ' , ' Y+ ' , ... | Encoding Arabic letters with their diacritics ( if exists ) |
Python | I have recently been working on creating a prime-number finding program . However , I came to notice that one function was much slower when it used arguments than when it used pre-set values.Across 3 different versions , it becomes clear that the variables are significantly slowing down the program , and I would like t... | def version1 ( n , p ) : return ( ( n*n - 2 ) & ( ( 1 < < p ) - 1 ) ) + ( ( n*n - 2 ) > > p ) timeit.timeit ( `` version1 ( 200 , 500000000 ) '' , `` from __main__ import version1 '' , number=100 ) def version2 ( ) : return ( ( 200*200 - 2 ) & ( ( 1 < < 500000000 ) - 1 ) ) + ( ( 200*200 - 2 ) > > 500000000 ) timeit.tim... | Why does using arguments make this function so much slower ? |
Python | I am working with a DataFrame which looks like thisand I am trying to compute the following output.In my current approach I 'm trying to iterate through the columns , then replace values with the contents of a third column.For example , if List [ 0 ] [ 1 ] is equal to Numb [ 1 ] [ 1 ] replace column List [ 0 ] [ 1 ] wi... | List Numb Name1 1 one1 2 two2 3 three4 4 four3 5 five List Numb Nameone 1 oneone 2 twotwo 3 threefour 4 fourthree 5 five | pandas map one column to the combination of two columns |
Python | It seems vims python sripting is designed to edit buffer and files rather than work nicely with vims registers . You can use some of the vim packages commands to get access to the registers but its not pretty.My solution for creating a vim function using python that uses a registeris something like this.Setting registe... | function printUnnamedRegister ( ) python < < EOFprint vim.eval ( ' @ @ ' ) EOFendfunction function setUnnamedRegsiter ( ) python < < EOFs = `` Some \ '' crazy\ '' string\nwith interesting characters '' vim.command ( 'let @ @ = '' % s '' ' % myescapefn ( s ) ) EOFendfunction function printUnnamedRegister ( ) python < < ... | Can you access registers from python functions in vim |
Python | I create an virtual environment in my conda named 'keras_ev ' and install the keras in it by after that when i the notebook does not show my keras_ev environment and i fail to import the keras in my notebook.Does anybody know how to fix this ! Thank you | conda install keras activate keras_evjupyter notebook | Keras installation |
Python | If I install one package Eg : pip install bpython on newly created virtualenv what I receive when I executeOutput : Question : Should we need to put all these in requirement.txt file or just bpython==0.17Once i was asked to clean up requirement.txt file , so i did updated the code from TOAnd I am still not sure whether... | pip freeze blessings==1.6.1bpython==0.17certifi==2018.1.18chardet==3.0.4curtsies==0.2.11greenlet==0.4.12idna==2.6Pygments==2.2.0requests==2.18.4six==1.11.0urllib3==1.22wcwidth==0.1.7 pip freeze > requirement.txt comm -12 < ( pip list -- format=freeze -- not-required ) < ( pip freeze ) > requirements.txt | Should we put all required and their dependent packages on requirement.txt or only required packages |
Python | I need to speed up the following code : N is around 30 , so the code is very slow ( it takes about 33 hours on my laptop ) . The argument of the function f ( ) is the binary representation of the index i , and f ( ) can be an arbitrary vectorizable function . I 'm not an expert , but in order to speed up the code , I w... | for i in range ( 0 , 2**N ) : output [ i ] = f ( np.array ( map ( int , bin ( i ) [ 2 : ] .zfill ( N ) ) ) ) list ( itertools.product ( [ 0 , 1 ] , repeat=N ) ) | How can I speed up this two-lines code ? |
Python | In sympy I have defined a two kets and a corresponding bra , when I apply the bra to the kets ... ... I get this result : How do I set 'Dead ' and 'Alive ' as orthogonal states , so that d.doit ( ) gives sqrt ( 2 ) /2 ? So far I 've only been able to substitute the brakets by hand : But how do I make the brakets evalua... | from sympy import sqrtfrom sympy.physics.quantum import Bra , Ket , qapplysuperpos = ( Ket ( 'Dead ' ) +Ket ( 'Alive ' ) ) /sqrt ( 2 ) d = qapply ( Bra ( 'Dead ' ) *superpos ) sqrt ( 2 ) * < Dead|Alive > /2 + sqrt ( 2 ) * < Dead|Dead > /2 d.subs ( Bra ( 'Dead ' ) *Ket ( 'Dead ' ) ,1 ) .subs ( Bra ( 'Dead ' ) *Ket ( 'Al... | Evaluate inner product of bra and ket in Sympy Quantum |
Python | Google Cloud Datastore is a non-relational database , and is built on the concept of eventual consistency . It also supplies a means to get strong consistency through ancestor queries and entity groups . However , I am not getting strong consistency when using ancestor queries within a transaction.Consider this : Since... | class Child ( ndb.Model ) : @ classmethod def create ( cls ) : child = cls ( ) child.put ( ) print Child.query ( ) .fetch ( ) Child.create ( ) [ ] class Parent ( ndb.Model ) : passclass Child ( ndb.Model ) : @ classmethod def create ( cls , parent ) : child = cls ( parent=parent ) child.put ( ) print Child.query ( ance... | Strong consistency within transactions in Google Cloud Datastore |
Python | I have the following C declaration of a struct : So pretty typical tree with some payload . I tried to rewrite this to the following ctypes declaration : This unfortunately did not work , because at that time python compiler does not know the type VNODE yet.So I rewrote it to the following class : This did not work , b... | struct vnode { char firstchar ; uint8_t wordlength ; bool is_red ; struct vnode *left ; struct vnode *right ; struct textelem *texts ; } ; class VNODE ( Structure ) : _fields_ = [ ( `` firstchar '' , c_char ) , ( `` wordlength '' , c_ubyte ) , ( `` is_red '' , c_bool ) , ( `` left '' , POINTER ( VNODE ) ) , ( `` right ... | How can I setup a Structure in ctypes with pointer to itself ? |
Python | In Perl one uses : In Python I found : But , what happens when the file given in the command line does NOT exist ? python test.py test1.txt test2.txt filenotexist1.txt filenotexist2.txt test3.txt was given as the argument.I tried various ways of using try : except : nextfile , but I could n't seem to make it work.For t... | while ( < > ) { # process files given as command line arguments } import fileinputfor line in fileinput.input ( ) : process ( line ) | What is the equivalent of Perl 's ( < > ) in Python ? fileinput does n't work as expected |
Python | With most Python interpreters that I 've used , Ctrl+C will cause the interpreter to print out `` KeyboardInterrupt '' and remain open . However , in a recent install on a new computer , Ctrl+C is causing the interpreter to exit , which is undesirable.Setting the signal.SIGINT handler still exits.There is n't a startup... | import timetry : time.sleep ( 100 ) except KeyboardInterrupt : pass | Windows Python interpreter exits on Ctrl+C |
Python | I want to read a file and write it back out . Here 's my code : This does n't work , why ? ? ? ? ? Edit : The rewritten file is corrupt ( python 2.7.1 on windows ) | file = open ( zipname , ' r ' ) content = file.read ( ) file.close ( ) alt = open ( ' x.zip ' , ' w ' ) alt.write ( content ) alt.close ( ) | Read a zip an write it to an other file python |
Python | Given a dataframe like this : How do I read it in using pd.read_clipboard ? I 've tried this : But it throws an error : How can I fix this ? Other pd.read_clipboard questions : How do you handle column names having spaces in them when using pd.read_clipboard ? How to handle custom named index when copying a dataframe u... | CA B 1.1 111 20 222 313.3 222 24 333 655.5 333 226.6 777 74 df = pd.read_clipboard ( index_col= [ 0 , 1 ] ) ParserError : Error tokenizing data . C error : Expected 2 fields in line 3 , saw 3 | Copying MultiIndex dataframes with pd.read_clipboard ? |
Python | I have 2 csv files with the same column names , but different values.The first column is the index ( time ) and one of the data columns is a unique identifier ( id ) The index ( time ) is different for each csv file.I have read the data into 2 dataframes using read_csv , giving me the following : I would like to create... | + -- -- -- -+ -- -- -- + -- -- -- -+ | id | size | price |+ -- -- -- -+ -- -- -- -+ -- -- -- + -- -- -- -+| time | | | |+ -- -- -- -+ -- -- -- -+ -- -- -- + -- -- -- -+| t0 | ID1 | 10 | 110 || t2 | ID1 | 12 | 109 || t6 | ID1 | 20 | 108 |+ -- -- -- -+ -- -- -- -+ -- -- -- + -- -- -- -+ + -- -- -- -+ -- -- -- + -- -- -- ... | pandas : concatenate dataframes , forward-fill and multiindex on column data |
Python | I 'm trying to build the Swagger settings for SecurityDefinition in order to get the following result in openapi.json : In my settings.py I have addded the following swagger settings : The issue is that in the openapi.json which generated by Swagger there is not the security dict and I have no clue how it is generated.... | `` securityDefinitions '' : { `` password '' : { `` type '' : `` oauth2 '' , `` tokenUrl '' : `` http : //example.com/oauth/token '' , `` flow '' : `` password '' , `` scopes '' : { `` write '' : `` allows modifying resources '' , `` read '' : `` allows reading resources '' } } } , '' security '' : [ { `` password '' :... | Django REST Swagger : How to use security section in Swagger settings ? |
Python | I 'm working with tkinter on Python 3.4.1 ( Windows 7 ) , and I 'm finding that ttk 's Entry.xview_moveto function is not working properly . Here is some simple code : The xview_moveto function should scroll the text all the way to the left , but it does n't . However , I noticed that if I useit works just fine . Why d... | from tkinter import *from tkinter import ttka = Tk ( ) text = StringVar ( a , value='qwertyuiopasdfghjklzxcvbnm1234567890 ' ) b = ttk.Entry ( a , textvariable=text ) b.grid ( ) b.xview_moveto ( 1 ) b.after ( 500 , b.xview_moveto , 1 ) | Why does tkinter 's Entry.xview_moveto fail ? |
Python | I have to solve the Travelling Salesman Problem using a genetic algorithm that I will have to write for homework.The problem consists of 52 cities . Therefore , the search space is 52 ! . I need to randomly sample ( say ) 1000 permutations of range ( 1 , 53 ) as individuals for the initial population of my genetic algo... | > > > random.sample ( itertools.permutations ( range ( 1 , 53 ) ) , 1000 ) Traceback ( most recent call last ) : File `` < stdin > '' , line 1 , in < module > File `` /usr/lib/python2.6/random.py '' , line 314 , in sample n = len ( population ) TypeError : object of type 'itertools.permutations ' has no len ( ) > > > r... | Sampling Permutations of [ 1,2,3 , ... , N ] for large N |
Python | I have a Tornado Python server which accepts a variable bitrate mp3 file one chunk at a time ( the chunks are made up of a fixed number of frames ) .All I am doing is passing that binary forward , however , I want to know the duration of the chunk . Because it is variable bitrate I can not do a simple calculation . I w... | def _on_read_frames ( self , data ) : logging.info ( 'read from input : \n % s ' , data ) binary_audio = base64.b64decode ( data ) # need to find out how many miliseconds went by here | Python decode MP3 in chunks on Mac OS |
Python | I have written a function in cython that will search a STL vector of strings for a given string and return true if it is found , false otherwise . Performance is very important here ! I would ideally like to have a templated function to do the same thing so I do n't have to write a function for each data type . I am su... | from libcpp cimport boolfrom libcpp.string cimport stringfrom libcpp.vector cimport vectorfrom cython.operator cimport dereference as deref , preincrement as inccpdef bool is_in_vector ( string a , vector [ string ] v ) : cdef vector [ string ] .iterator it = v.begin ( ) while it ! = v.end ( ) : if deref ( it ) == a : ... | Templated STL containers as argument to function in cython |
Python | As mentioned here , Below code , Output : Question : Why __eq__ gets called on accessing jimbut not on bob ? | class Person ( object ) : def __init__ ( self , name , ssn , address ) : self.name = name self.ssn = ssn self.address = address def __hash__ ( self ) : print ( 'in hash ' ) return hash ( self.ssn ) def __eq__ ( self , other ) : print ( 'in eq ' ) return self.ssn == other.ssnbob = Person ( 'bob ' , '1111-222-333 ' , Non... | When does __eq__ gets called using hash ( ) ? |
Python | I 'm starting to learn to use google app engine and , in much of the code I 've come across , they declare the instance of the webapp.WSGIApplication as a global variable . This does n't seem to be necessary , as the code works fine when it is locally declared in the main function.I was always advised that global varia... | class Guestbook ( webapp.RequestHandler ) : def post ( self ) : greeting = Greeting ( ) if users.get_current_user ( ) : greeting.author = users.get_current_user ( ) greeting.content = self.request.get ( 'content ' ) greeting.put ( ) self.redirect ( '/ ' ) application = webapp.WSGIApplication ( [ ( '/ ' , MainPage ) , (... | Why is an instance of webapp.WSGIApplication always defined as a global variable in google app engine code ? |
Python | I 've been learning Ruby and Python concurrently and one of the things I noticed is that these 2 languages seem to treat scope differently . Here 's an example of what I mean : It appears that def block can access variables declared outside of its immediate scope in Python but not in Ruby . Can someone confirm whether ... | # Pythona = 5def myfunc ( ) : print amyfunc ( ) # = > Successfully prints 5 # Rubya = 5def myfunc puts aendmyfunc # = > Throws a `` NameError : undefined local variable or method ` a ' for main : Object '' | Scope in Ruby and Python |
Python | I 'm in the process of writing my first RESTful web service atop GAE and the Python 2.7 runtime ; I 've started out using Guido 's shiny new ndb API.However , I 'm unsure how to solve a particular case without the implicit back-reference feature of the original db API . If the user-agent requests a particular resource ... | class Contact ( ndb.Expando ) : `` '' '' The One `` '' '' # basic info name = ndb.StringProperty ( ) birth_day = ndb.DateProperty ( ) # If I were using db , a collection called 'phone_numbers ' would be implicitly # created here . I could use this property to retrieve related phone numbers # when this entity was querie... | Following backreferences of unknown kinds in NDB |
Python | GivenI 'd likeCurrently I have brute forced it with : Finally , I 'd like to get toby running this right to left . Currently I haveI 'm not fussy about inplace or create a new list , but right now this smells to me . I ca n't see a way to store a temporary 'last ' value and use map/lambda , and nothing else is coming t... | a = [ None,1,2,3 , None,4 , None , None ] a = [ None,1,2,3,3,4,4,4 ] def replaceNoneWithLeftmost ( val ) : last = None ret = [ ] for x in val : if x is not None : ret.append ( x ) last = x else : ret.append ( last ) return ret a = [ 1,1,2,3,3,4,4,4 ] def replaceNoneWithRightmost ( val ) : return replaceNoneWithLeftmost... | Replace None in list with leftmost non none value |
Python | I want to convert a DICOM image from int16 to uint8 . I have done it in Python using Z_axis = bytescale ( img ) , but this gives different results than using im2uint8 in MATLAB . In MATLAB , The minimum and maximum values of a DICOM image after converting to uint8 using im2uint8 are ( 124 , 136 ) , respectively . But t... | for person in range ( 0 , len ( dirs1 ) ) : if not os.path.exists ( os.path.join ( directory , dirs1 [ person ] ) ) : Pathnew = os.path.join ( directory , dirs1 [ person ] ) os.makedirs ( Pathnew ) for root , dirs , files in os.walk ( os.path.join ( path , dirs1 [ person ] ) ) : dcmfiles = [ _ for _ in files if _.endsw... | Difference between the functions `` im2uint8 '' ( in MATLAB ) and `` bytescale '' ( in Python ) |
Python | I try to run a simple linear fit in scikit-learn : As a result I get : Does anybody know what is the reason of this problem and how the problem can be resolved ? P.S . I use the version 0.16.1 of scikit-learn . But I had this problem also with an older version . I do it under Ubuntu.ADDEDToday I have tried another esti... | from sklearn import linear_modelclf = linear_model.LinearRegression ( ) clf.fit ( [ [ 0 , 0 ] , [ 1 , 1 ] , [ 2 , 2 ] ] , [ 0 , 1 , 2 ] ) Illegal instruction ( core dumped ) | Why does scikit-learn cause core dumped ? |
Python | Why is utc == 2016-11-27 22:46:00+00:00instead of 2016-11-27 21:46:00+00:00Thanks | > > > t = datetime.datetime ( 2016 , 11 , 27 , 14 , 46 , 0 , 0 ) tz = pytz.timezone ( 'America/Vancouver ' ) utc = tz.localize ( t ) .astimezone ( pytz.utc ) now = datetime.datetime.utcnow ( ) > > > print t , tz , utc , now2016-11-27 14:46:00 America/Vancouver 2016-11-27 22:46:00+00:00 2016-10-27 21:49:33.723605 | Converting local time to UTC using pytz adds DST ? |
Python | How can I most optimally remove identical items from a list and sort it in Python ? Say I have a list : I could iterate over a copy of the list ( since you should not mutate the list while iterating over it ) , item for item , and remove all of the item except for one : Which removes the redundant items : and then sort... | my_list = [ ' a ' , ' a ' , ' b ' , ' c ' , 'd ' , ' a ' , ' e ' , 'd ' , ' f ' , ' e ' ] for item in my_list [ : ] : # must iterate over a copy because mutating it count = my_list.count ( item ) # see how many are in the list if count > 1 : for _ in range ( count-1 ) : # remove all but one of the element my_list.remov... | How do I remove identical items from a list and sort it in Python ? |
Python | The error that I am getting when I use import torchvision is this : Error MessageI do n't know what to do . I have tried changing the version of python from the native one to the one downloaded through anaconda . I am using anaconda as a package manager and have installed torch vision through anaconda as well as throug... | `` *Traceback ( most recent call last ) : File `` /Users/gokulsrin/Desktop/torch_basics/data.py '' , line 4 , in < module > import torchvisionModuleNotFoundError : No module named 'torchvision'* '' | Despite installing the torch vision pytorch library , I am getting an error saying that there is no module named torch vision |
Python | I am using : SQLAlchemy 0.7.9 and Python 2.7.3 with Bottle 0.11.4 . I am an amateur at python.I have a class ( with many columns ) derived from declarative base like this : I am currently using this 'route ' in Bottle to dump out a row/class in json like this : My first question is : How can I have each column have som... | class Base ( object ) : @ declared_attr def __tablename__ ( cls ) : return cls.__name__.lower ( ) id = Column ( Integer , primary_key = True ) def to_dict ( self ) : serialized = dict ( ( column_name , getattr ( self , column_name ) ) for column_name in self.__table__.c.keys ( ) ) return serializedBase = declarative_ba... | SQLAlchemy Declarative : Adding a static text attribute to a column |
Python | How do I check if two file pointers point to the same file or not.My use case is I am watching a file for changes and doing something , but logback rolls over this file to old date and creates a new file . But the file pointer variable in python is still pointing to the old file . If fp1 ! = fp2 , I would like to updat... | > > > fp1 = open ( `` /data/logs/perf.log '' , `` r '' ) > > > fp1 < open file '/data/logs/perf.log ' , mode ' r ' at 0x7f5adc07cc00 > > > > fp2 = open ( `` /data/logs/perf.log '' , `` r '' ) > > > fp2 < open file '/data/logs/perf.log ' , mode ' r ' at 0x7f5adc07cd20 > > > > fp1 == fp2False > > > fp1 is fp2False mv /da... | Check if two file pointers point to same file in Python |
Python | Is it possible to change or assign new parent to the Model instance that already in datastore ? For example I need something like thisbut it does n't works this way because task.parent is built-in method . I was thinking about creating a new Key instance for the task but there is no way to change key as well.Any though... | task = db.get ( db.Key ( task_key ) ) project = db.get ( db.Key ( project_key ) ) task.parent = projecttask.put ( ) | Change|Assign parent for the Model instance on Google App Engine Datastore |
Python | I am trying to extract some features from a given document , given a pre-defined set of features . However the output , is a 2x3 array , filled in with zeros instead of : Any help would be much appreciated | from sklearn.feature_extraction.text import CountVectorizerfeatures = [ ' a ' , ' b ' , ' c ' ] doc = [ ' a ' , ' c ' ] vectoriser = CountVectorizer ( ) vectoriser.vocabulary = featuresvectoriser.fit_transform ( doc ) desired_output = [ [ 1 , 0 , 0 ] [ 0 , 0 , 1 ] ] | CountVectorizer returns only zeros |
Python | Given the following Python function : If I turn it into a UDF and apply it to a column object , it works ... ... Except if the column is generated by rand : However , the following two work : The error : Why does this happen , and how can I use a rand column expression created within a UDF ? | def f ( col ) : return col from pyspark.sql import functions as Ffrom pyspark.sql.types import DoubleTypedf = spark.range ( 10 ) udf = F.udf ( f , returnType=DoubleType ( ) ) .asNondeterministic ( ) df.withColumn ( 'new ' , udf ( F.lit ( 0 ) ) ) .show ( ) df.withColumn ( 'new ' , udf ( F.rand ( ) ) ) .show ( ) # fails ... | Why does a PySpark UDF that operates on a column generated by rand ( ) fail ? |
Python | In my country many websites get censored and blocked and are instead redirected to a certain page . I do n't know how they exactly do this . But is it possible to programmatically determine if a website is blocked or is not blocked without loading the whole thing ? The reason I want to do this is to use a web search AP... | < html > < head > < meta http-equiv= '' Content-Type '' content= '' text/html ; charset=windows-1256 '' > < title > M3-5 < /title > < /head > < body > < iframe src= '' http : //10.10.34.34 ? type=Invalid Site & policy=MainPolicy `` style= '' width : 100 % ; height : 100 % '' scrolling= '' no '' marginwidth= '' 0 '' mar... | Checking website redirection , programmatically |
Python | I 'm trying to figure out if I can speed up the generation of permutations . Specifically I 'm using 8 out of [ a-z ] and I 'd like to use 8 out of [ a-zA-Z ] and 8 out of [ a-zA-Z0-9 ] . Which I know will quickly take a great deal of time and space.Even just a permutation of length 8 from the lowercase ASCII character... | import stringimport itertoolsfrom itertools import permutationscomb = itertools.permutations ( string.ascii_lowercase , 8 ) f = open ( '8letters.txt ' , ' w ' ) for x in comb : y = `` .join ( x ) f.write ( y + '\n ' ) f.close ( ) | Can generating permutations be done in parallel ? |
Python | I am trying to write an `` enum class '' in python . A slight nuisance I am currently experiencing is the inability to define enum values inside the enum class . That is , I can do this : But I would like to do this , or a similarly legible equivalent : Unfortunately , I am getting the following error : name 'Fruit ' i... | class Fruit : def __init__ ( self , name ) : self.name = nameclass Fruits ( Enum ) : Apple = Fruit ( `` apple '' ) class Fruit ( Enum ) : def __init__ ( self , name ) : self.name = name Apple = Fruit ( `` apple '' ) | Python 2.x - creating static instance of class in same class |
Python | I am trying to get two variables from one input like this : But I want to make the y variable optional , so if the user only inputs x it would only print that value . I get a ValueError if only inserted the x argument.Anyone knows how to do this ? | x , y = input ( ) .split ( ) print ( x , y ) | Make an input optional in Python |
Python | Using python 3 , one has the option to use typehints . My question is , if a function returns None , should one add this , or leave it blank.i.e.And which PEP addresses this ? | def hint ( p : str ) - > None : passdef no_hint ( p : str ) : pass | typehints - > None or leave blank |
Python | In a previous life I did a fair bit of Java development , and found JUnit Theories to be quite useful . Is there any similar mechanism for Python ? Currently I 'm doing something like : But this is rather clunky , if the first `` case '' fails , all others fail to be run . | def some_test ( self ) : cases = [ ( 'some sample input ' , 'some expected value ' ) , ( 'some other input ' , 'some other expected value ' ) ] for value , expected in cases : result = method_under_test ( value ) self.assertEqual ( expected , result ) | Unit test Theories in Python ? |
Python | From here : Return a proxy object that delegates method calls to a parent or sibling class of type . This is useful for accessing inherited methods that have been overridden in a class . The search order is same as that used by getattr ( ) except that the type itself is skipped . If the second argument is omitted , the... | super ( [ type [ , object-or-type ] ] ) | What is the type of the super object returned by super ( ) ? |
Python | I am trying to create an excel workbook using xlsxwriter , but when I try to do workbook.close ( ) i get following exception : I am querying a database , then creating 3 sheets and filling tables in them , this is the code : The above code works perfectly fine in python3 on my local machine , however on server we are t... | Traceback ( most recent call last ) : File `` /usr/local/bin/fab '' , line 11 , in < module > sys.exit ( program.run ( ) ) File `` /usr/local/lib/python2.7/site-packages/invoke/program.py '' , line 363 , in run self.execute ( ) File `` /usr/local/lib/python2.7/site-packages/invoke/program.py '' , line 532 , in execute ... | Unable to close worksheet in xlsxwriter |
Python | I believe I 'm getting bitten by some combination of nested scoping rules and list comprehensions . Jeremy Hylton 's blog post is suggestive about the causes , but I do n't really understand CPython 's implementation well-enough to figure out how to get around this . Here is an ( overcomplicated ? ) example . If people... | import itertoolsdef digit ( n ) : digit_list = [ ( x , False ) for x in xrange ( 1 , n+1 ) ] digit_list [ 0 ] = ( 1 , True ) return itertools.cycle ( digit_list ) > > > D = digit ( 5 ) > > > [ D.next ( ) for x in range ( 5 ) ] # # This list comprehension works as expected [ ( 1 , True ) , ( 2 , False ) , ( 3 , False ) ... | Unexpected list comprehension behaviour in Python |
Python | print.__doc__ outputs : where asOutputs : Prints the values to a stream , or to sys.stdout by default . Optional keyword arguments : file : a file-like object ( stream ) ; defaults to the current sys.stdout . sep : string inserted between values , default a space . end : string appended after the last value , default a... | SyntaxError : invalid syntax > > > getattr ( __builtin__ , '' print '' ) .__doc__ print ( value , ... , sep= ' ' , end='\n ' , file=sys.stdout ) | print.__doc__ vs getattr ( __builtin__ , '' print '' ) .__doc__ |
Python | Today I had a python exam where following question was asked : Given the following code extract , Complete the code so the output is : 10 7 5.How is it possible to get such output in python using range function ? | nums = list ( range ( ? , ? , ? ) ) print ( nums ) | Python range with Uneven gap |
Python | My problem StringPrint result : This works fine , I just write the string `` CT142H.0000 '' by hand tiping with keyboard ( Its the same code ) Print result : Why python encode the first string when I append it into a list ? -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -This is currently solved ,... | # -*- coding : utf-8 -*-print ( `` # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # '' ) foo = `` СТ142Н.0000 '' print ( type ( foo ) ) print ( `` foo : `` +foo ) foo_l = [ ] foo_l.append ( foo ) print ( `` List : `` ) print ( foo_l ) print ( `` List decode : `` ) print ( [ x.decode ( `` UTF-8 '' ) for x... | Python 2.7 - Why python encode a string when .append ( ) in a list ? |
Python | I 'm trying to interact with an NCURSES program.As an example I 'm using GNU Screen and run aptitude inside . ( you could try it with mc instead . ) The program below starts a screen session with -x to connect to my session.I want to navigate by pressing Arrow-down and Arrow-up.If I send ' q ' for quit I see a box pop ... | from twisted.internet import protocol , reactorclass MyPP ( protocol.ProcessProtocol ) : def connectionMade ( self ) : reactor.callLater ( 1.0 , self.foo ) def foo ( self ) : self.transport.write ( '\033 [ B ' ) def processExited ( self , reason ) : print `` processExited , status % s '' % ( reason.value.exitCode , ) d... | How do I interact with a child process pretending to be a terminal ? |
Python | for a project , I am using Django on the back-end and AngularJs on the front end.Basically , what I want is to run the Angular app only when the url starts with projectkeeper/.In other words , lets say my website is example.com . I want the angular app to run for the URLs example.com/projectkeeper/dashboard/ , example.... | urlpatterns = [ url ( r'^projectkeeper/ $ ' , TemplateView.as_view ( template_name='base.html ' ) ) , ] myapp.config ( [ ' $ routeProvider ' , function ( $ routeProvider ) { $ routeProvider .when ( '/dashboard/ ' , { title : 'Dashboard ' , controller : 'DashboardController ' , templateUrl : 'static/app_partials/project... | Using Django URLs with AngularJs routeProvider |
Python | I use the Python-Qt bindings from PySide and I want to draw a scene with amongst others a rectangle and the rectangle is not fully visible because the view should only show a part of the scene where the rectangle is not fully contained.Here is a minimal example : I expect to see the lower part of a rectangle instead I ... | from PySide.QtGui import *app = QApplication ( [ ] ) scene = QGraphicsScene ( ) scene.addRect ( 0 , 0 , 100 , 100 ) view = QGraphicsView ( scene ) view.setSceneRect ( -60 , 20 , 100 , 100 ) view.show ( ) app.exec_ ( ) | Why is a rectangle partly outside of view drawn as a triangle ? |
Python | I 'm having trouble with encodings.I 'm using version Python 2.7.2+ ( default , Oct 4 2011 , 20:03:08 ) [ GCC 4.6.1 ] on linux2I have chars with accents like é à.My scripts uses utf-8 encoding Users can type strings usings raw_input ( ) with .called in the main loop 'pseudo ' shellData are stored as pickle in files.I m... | # ! /usr/bin/python # -*- coding : utf-8 -*- def rlinput ( prompt , prefill= '' ) : readline.set_startup_hook ( lambda : readline.insert_text ( prefill ) ) try : return raw_input ( prompt ) finally : readline.set_startup_hook ( ) while to_continue : to_continue , feedback = action ( unicode ( rlinput ( u'todo > ' ) , '... | Lost with encodings ( shell and accents ) |
Python | After getting back into Python , I 'm starting to notice and be annoyed more and more by my C # coding style requiring braces everywherepreferring the ( subjective ) much cleaner looking python counter-partis there any way I can go about hiding these braces ( as they do take up about 30 % of my coding screen on average... | if ( ... ) { return ... ; } else { return ... ; } if ... : return ... else return ... | Hide curly braces in C # |
Python | A colleague of mine wrote code analogous to the following today , asked me to have a look , and it took me a while to spot the mistake : The problem here is that there 's no self parameter to super ( ) in B 's constructor . What surprised me is that absolutely nothing happens in this case , i.e . no error , nothing . W... | class A ( ) : def __init__ ( self ) : print ( ' A ' ) class B ( A ) : def __init__ ( self ) : super ( B ) .__init__ ( ) b = B ( ) | Second parameter of super ( ) ? |
Python | I can see two very similar ways of having properties in Python ( a ) Property class ( b ) Property decoratorQuestionAre those two pieces of code identical ( e.g . bytecode wise ) ? Do they show the same behavior ? Are there any official guides which `` style '' to use ? Are there any real advantages of one over the oth... | class Location ( object ) : def __init__ ( self , longitude , latitude ) : self.set_latitude ( latitude ) self.set_longitude ( longitude ) def set_latitude ( self , latitude ) : if not ( -90 < = latitude < = 90 ) : raise ValueError ( 'latitude was { } , but has to be in [ -90 , 90 ] ' .format ( latitude ) ) self._latit... | Is there an advantage of using the property decorator compared to the property class ? |
Python | I have the following list : seqList = [ 0 , 6 , 1 , 4 , 4 , 2 , 4 , 1 , 7 , 0 , 4 , 5 ] I want to print the items in the list only when it is present more than once ( in this case value 1 and 4 ) and I want to ignore the first value in the list ( in this case value 0 ) To count how many times each value is present in t... | from collections import CounterseqList = [ 0 , 6 , 1 , 4 , 4 , 2 , 4 , 1 , 7 , 0 , 4 , 6 ] c = dict ( Counter ( seqList ) ) print ( c ) { 0 : 2 , 6 : 1 , 1 : 2 , 4 : 4 , 2 : 1 , 7 : 1 , 5 : 1 } -value 1 appears multiple times ( 2 times ) -value 4 appears multiple times ( 4 times ) | How do I print values only when they appear more than once in a list in python |
Python | I ca n't find concise information about what is going on in this very simple program : The output of this simple test is : I clearly do not understand how python handles each case . Could any one provide a link so that I can read about it , or a short explanation of what is happening ? Thanks a lot . | print 'case 1 ' # a and b stay differenta = [ 1,2,3 ] b = ab = [ 4,5,6 ] print ' a = ' , aprint ' b = ' , bprintprint 'case 2 ' # a and b becomes equala = [ 1,2,3 ] b = ab [ 0 ] = 4 b [ 1 ] = 5 b [ 2 ] = 6 print ' a = ' , aprint ' b = ' , bprintprint 'case 3 ' # a and b stay different nowa = [ 1,2,3 ] b = a [ : ] b [ 0... | Python variable handling , I do n't understand it |
Python | Lets say I have a table that look like this : I want to get rid of the Date column , then aggregate by Company AND region to find the average of Count and sum of Amount.Expected output : I looked into this post here , and many other posts online , but seems like they are only performing one kind of aggregation action (... | Company Region Date Count AmountAAA XXY 3-4-2018 766 8000AAA XXY 3-14-2018 766 8600AAA XXY 3-24-2018 766 2030BBB XYY 2-4-2018 66 3400BBB XYY 3-18-2018 66 8370BBB XYY 4-6-2018 66 1380 Company Region Count AmountAAA XXY 766 18630BBB XYY 66 13150 aggregation = { 'Count ' : { 'Total Count ' : 'mean ' } , 'Amount ' : { 'Tot... | pandas : how to group by multiple columns and perform different aggregations on multiple columns ? |
Python | This is the same question as this question , which is marked as a duplicate of this one.The problem , and the reason I 'm still asking , is that the solution provided ( using pandas.read_clipboard ( ) ) currently does n't work.I use Python 3.5 and whenever I try to copy data from the clipboard I get an error : '' It se... | c1 c2 c3 c40 1 2 2 11 1 3 2 32 3 4 4 33 4 5 6 54 5 6 9 7 | Pasting data into a pandas dataframe |
Python | I am using opencv module to read and write the image . here is the code and below is the image i am reading and second image is after saving it on disk using cv2.imwrite ( ) . It is significantly visible that colors are dull in second image . Is there any workaround to this problem or I am missing on some sort of setti... | import cv2img = cv2.imread ( 'originalImage.jpg ' ) cv2.imwrite ( 'test.jpg ' , img ) | Color gets dull : opencv cv2.imread cv2.imwrite |
Python | I am new to python decorators . I have understood the basic concepts with the help of simple examples . But when I tried to read this more practical decorator , I feel lost . Given below is the code followed by my questions : My doubts : When we prefix the decorator to a function , does that mean that we are creating a... | class countcalls ( object ) : `` Decorator that keeps track of the number of times a function is called . '' __instances = { } def __init__ ( self , f ) : self.__f = f self.__numcalls = 0 countcalls.__instances [ f ] = self def __call__ ( self , *args , **kwargs ) : self.__numcalls += 1 return self.__f ( *args , **kwar... | Unable to understand this python decorator |
Python | Using Django 1.6 and Rest Framework 2 . I have a uri below that I want to present a second resource as a child of that resource , with create , list , get and delete methodsI am new and still learning , I tried this url config : then registering the router I added : and the following viewset : The error I am getting ( ... | /rest/parent_resource/951 /rest/parent_resource/951/child_resource router.register ( r'parent_resource ' , diliMarketplace.MarketPlaceProposalViewSet_Internal ) url ( r'^rest/parent_resource/ ( ? P < parent_resource_pk > [ 0-9 ] + ) /child_resource/ $ ' , ChildViewset.as_view ( ) ) url ( r'^rest/ ' , include ( router.u... | routing one rest resource as a child of a second rest resource |
Python | When I have this codeYou can write your name after that string . But , how to have something display at the end of the input ? So no matter what you write , the ' ) ' character appears as you are writing ? | input ( 'Write your name : ' ) > > > Write your name : My name > > > Write your name : ( Name ) > > > Write your name : ( Name Name ) > > > Write your name : ( Name Name Name ) | How to input text between two strings ? |
Python | For example , the implementation of Keras ' Adagrad has been : And the Function 'get_update ( ) ' seems one step update . However should the accumulators be stored the history information ? Why it has been initialized to zeros at each step ? How it can be an accumulator through the whole training process ? What does th... | class Adagrad ( Optimizer ) : '' '' '' Adagrad optimizer.It is recommended to leave the parameters of this optimizerat their default values. # Arguments lr : float > = 0 . Learning rate . epsilon : float > = 0. decay : float > = 0 . Learning rate decay over each update. # References - [ Adaptive Subgradient Methods for... | How Adagrad works in Keras ? What does self.weights mean in Keras Optimizer ? |
Python | I was looking at how Python implements the property descriptor internally . According to the docs property ( ) is implemented in terms of the descriptor protocol , reproducing it here for convenience : My question is : why are n't the last three methods implemented as follows : Is there a reason for returing new instan... | class Property ( object ) : `` Emulate PyProperty_Type ( ) in Objects/descrobject.c '' def __init__ ( self , fget=None , fset=None , fdel=None , doc=None ) : self.fget = fget self.fset = fset self.fdel = fdel if doc is None and fget is not None : doc = fget.__doc__ self.__doc__ = doc def __get__ ( self , obj , objtype=... | Python property descriptor design : why copy rather than mutate ? |
Python | I have a python project where I use : pipenvtoxpytestand many more.Basically , I want to add tox to my gitlab pipelines . And almost everything seems to work , calling mypy , flake8 or black from tox works fine . But when I call tox -e py37 ( so I want to run the tests ) with coverage enabled , the tests are run , I ca... | [ tox ] envlist = flake8 , mypy , black , py37 [ testenv ] extras = testscommands= pytest -- cov -ra -- tb=short { posargs } [ run ] branch = Truesource = fooomit = foo/__init__.py foo/__main__.py foo/bar/__init__.py foo/baz/__init__.py [ report ] exclude_lines = pragma : no cover if __name__ == .__main__.show_missing ... | Tox 0 % coverage |
Python | To find the loss during training a model we can use cntk.squared_error ( ) function , like this : But I am interested in finding the loss in terms of absolute error . The below code does n't work : It gives error as : AttributeError : module 'cntk ' has no attribute 'absolute_error'Is there any inbuilt function in CNTK... | loss = cntk.squared_error ( z , l ) loss = cntk.absolute_error ( z , l ) | CNTK absolute error |
Python | I want to selectively hide some resources based on some form of authentication in web.py , but their existence is revealed by 405 responses to any HTTP method that I have n't implemented.Here 's an example : When an undefined method request is issued , the resource is revealed : I could implement the same check for the... | import weburls = ( '/secret ' , 'secret ' , ) app = web.application ( urls , globals ( ) ) class secret ( ) : def GET ( self ) : if web.cookies ( ) .get ( 'password ' ) == 'secretpassword ' : return `` Dastardly secret plans ... '' raise web.notfound ( ) if __name__ == `` __main__ '' : app.run ( ) $ curl -v -X DELETE h... | web.py : How to selectively hide resources with 404s for any HTTP method ? |
Python | I ’ m using django-allauth to authenticate users ( uses Patreon 's API v1 ) , which adds a json to the database with the info below . I would like to show extra content on the site if the user 's pledge matches a particular tier ( or is above one ) .At first I though relationships.pledges.data.id would have the ID of t... | { `` attributes '' : { `` about '' : null , `` can_see_nsfw '' : true , `` created '' : `` 2019-05-20T20:29:02.000+00:00 '' , `` default_country_code '' : null , `` discord_id '' : null , `` email '' : `` admin @ email.com '' , `` facebook '' : null , `` facebook_id '' : null , `` first_name '' : `` Adm '' , `` full_na... | How to find user 's patreon pledge tier using django-allauth for authentication |
Python | I have a class that need to make some magic with every operator , like __add__ , __sub__ and so on.Instead of creating each function in the class , I have a metaclass which defines every operator in the operator module.The approach works fine , but I think It would be better if I generate the replacement operator only ... | import operatorclass MetaFuncBuilder ( type ) : def __init__ ( self , *args , **kw ) : super ( ) .__init__ ( *args , **kw ) attr = '__ { 0 } { 1 } __ ' for op in ( x for x in dir ( operator ) if not x.startswith ( '__ ' ) ) : oper = getattr ( operator , op ) # ... I have my magic replacement functions here # ` func ` f... | Intercept operator lookup on metaclass |
Python | I 've been using the dis module to observe CPython bytecode . But lately , I 've noticed some inconvenient behavior of dis.dis ( ) .Take this example for instance : I first define a function multiplier with a nested function inside of it inner : I then use dis.dis ( ) to disassemble it : As you can see , it disassemble... | > > > def multiplier ( n ) : def inner ( multiplicand ) : return multiplicand * n return inner > > > > > > from dis import dis > > > dis ( multiplier ) 2 0 LOAD_CLOSURE 0 ( n ) 3 BUILD_TUPLE 1 6 LOAD_CONST 1 ( < code object inner at 0x7ff6a31d84b0 , file `` < pyshell # 12 > '' , line 2 > ) 9 LOAD_CONST 2 ( 'multiplier.... | Is there a way to make dis.dis ( ) print code objects recursively ? |
Python | I have pandas dataframe of length 7499042 like this : each value in pandas dataframe is numpy array of length 50.Now I am extracting it like this : I have layers like this : But when I am passing my input to this while training . It is showing the error : The shape of input it is showing is ( 7499042 , ) . Please help ... | ' X ' ' y ' [ 0.1,0.2 ... ] 0.2 [ 0.3,0.4 , .. ] 0.3.. input = df [ ' X ' ] .values main_input = Input ( shape= ( 50,1 ) , name='main_input ' ) lstm_out=LSTM ( 32 , activation='tanh ' , recurrent_activation='sigmoid ' , return_sequences=True ) mean_pooling=AveragePooling1D ( pool_size=2 , strides=2 , padding='valid ' )... | Keras : ValueError : Error when checking input |
Python | I have a file with x number of string names and their associated IDs . Essentially two columns of data.What I would like , is a correlation style table with the format x by x ( having the data in question both as the x-axis and y axis ) , but instead of correlation , I would like the fuzzywuzzy library 's function fuzz... | import pandas as pdfrom fuzzywuzzy import fuzzdf = pd.read_csv ( 'random_data_file.csv ' ) df = df [ [ 'ID ' , 'String ' ] ] df [ 'String_Dup ' ] = df [ 'String ' ] # creating duplicate of data in questiondf = df.set_index ( 'ID ' ) df = df.groupby ( 'ID ' ) [ [ 'String ' , 'String_Dup ' ] ] .apply ( fuzz.ratio ( ) ) | Python fuzzy string matching as correlation style table/matrix |
Python | Python classes have this neat feature where you can decorate a class method with the @ property decorator , which makes the method appear as a statically-valued member rather than a callable . For example , this : results in the following behavior : So finally , my question : is there any built-in syntax that provides ... | class A ( object ) : def my_method ( self ) : return `` I am a return value . '' @ property def my_property ( self ) : return `` I am also a return value . '' > > > a = A ( ) > > > a.my_method ( ) ' I am a return value . ' > > > a.my_property ' I am also a return value . ' | Is there an equivalent to Python-style class properties in ES6 ? |
Python | I have a model : What is the impact of changing unique_together to Should I be careful before deploying this update ? There are more than 150.000 users online at the same time , what could happen in the worst case ? | class MyModel ( models.Model ) : name = models.CharField ( max_length=10 ) nickname = models.CharField ( max_length=10 ) title = models.CharField ( max_length=10 ) score = models.CharField ( max_length=10 ) class Meta : unique_together = [ 'name ' , 'nickname ' ] unique_together = [ 'name ' , 'title ' ] | django - unique_together change - any danger in prod db ? |
Python | As any Python programmer knows , you should use == instead of is to compare two strings for equality . However , are there actually any cases where ( s is `` '' ) and ( s == `` '' ) will give different results in Python 2.6.2 ? I recently came across code that used ( s is `` '' ) in code review , and while pointing out... | > > > a = `` '' > > > b = `` abc '' [ 2:2 ] > > > c = `` .join ( [ ] ) > > > d = re.match ( ' ( ) ' , 'abc ' ) .group ( 1 ) > > > e = a + b + c + d > > > a is b is c is d is eTrue | Can ( s is `` '' ) and ( s == `` '' ) ever give different results in Python 2.6.2 ? |
Python | Consider this dictionary of pandas series . The index on all series are integers and have some potential overlap , but certainly do not coincide . I made an observation that pd.concat seems slow when combining things along axis=1 when I have large indices , lots of non-overlap , and many items to concatenate . It promp... | dict_of_series = { 's % s ' % i : pd.Series ( 1 , np.unique ( np.random.randint ( 1000 , 10000 , size=1000 ) ) ) for i in range ( 100 ) } % % timeitpd.concat ( dict_of_series , axis=0 ) .unstack ( 0 ) % % timeitpd.concat ( dict_of_series , axis=1 ) | Why is pd.concat ( { } , axis=1 ) slower than pd.concat ( { } , axis=0 ) .unstack ( 0 ) ? |
Python | From my understanding , is supposed to close the file once the with statement completed . However , now I seein one place , looked around and figured out , that closing is supposed to close the file upon finish of the with statement.So , what 's the difference between closing the file and closing the file ? | with open ( ... ) as x : with closing ( open ( ... ) ) as x : | What is the difference between 'with open ( ... ) ' and 'with closing ( open ( ... ) ) ' |
Python | I would like to plot the surface of my data which is given by 3D vectors in cartesian coordinates x , y , z . The data can not be represented by a smooth function.So first we generate some dummy data with the function eq_points ( N_count , r ) which returns an array points with the x , y , z coordinates of each point o... | # credit to Markus Deserno from MPI # https : //www.cmu.edu/biolphys/deserno/pdf/sphere_equi.pdfdef eq_points ( N_count , r ) : points = [ ] a = 4*np.pi*r**2/N_count d = np.sqrt ( a ) M_theta = int ( np.pi/d ) d_theta = np.pi/M_theta d_phi = a/d_theta for m in range ( M_theta ) : theta = np.pi* ( m+0.5 ) /M_theta M_phi... | How can I plot the surface of a structure which is given by vectors in python ? |
Python | I have a column of string names , and I would like to find often occuring patterns ( words ) .Is there a way to return , say , strings with a higher ( or equal ) length than X , and occur more often than Y times in the the whole column ? Referring to the comment by Tim : I would like the nested ones to be removed , so ... | column < - c ( `` bla1okay '' , `` okay1243bla '' , `` blaokay '' , `` bla12okay '' , `` okaybla '' ) getOftenOccuringPatterns < - function ( ... .. ) getOftenOccuringPatterns ( column , atleaststringsize=3 , atleasttimes=4 ) > what times [ 1 ] bla 5 [ 2 ] okay 5 getOftenOccurringPatterns ( column , atleaststringsize=3... | Get often occuring string patterns from column in R or Python |
Python | Say I have an expression as follows : One could factorize it as : or asor asamong other possibilities . For other expressions , the # of possibilities can be much larger.My question is , does SymPy have any utility that allows the user to choose which of them to display ? Is there a way to specify the common factor/s t... | a*b*c + b*c + a*d b* ( a*c + c ) + ( a*d ) c* ( a*b + b ) + ( a*d ) a*d + b*c* ( a + 1 ) a , b , c , d = symbols ( `` a , b , c , d '' ) # These two equations are mathematically equivalent : eq1 = a*b*c + b*c + a*deq2 = a*d + b*c* ( a + 1 ) print collect ( eq1 , a ) print collect ( eq2 , a ) a* ( b*c + d ) + b*ca*d + b... | Choosing between different expression factorizations in SymPy |
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