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| # encoding: utf-8 | |
| """ | |
| Utilities for working with strings and text. | |
| Inheritance diagram: | |
| .. inheritance-diagram:: IPython.utils.text | |
| :parts: 3 | |
| """ | |
| import os | |
| import re | |
| import string | |
| import sys | |
| import textwrap | |
| from string import Formatter | |
| from pathlib import Path | |
| # datetime.strftime date format for ipython | |
| if sys.platform == 'win32': | |
| date_format = "%B %d, %Y" | |
| else: | |
| date_format = "%B %-d, %Y" | |
| class LSString(str): | |
| """String derivative with a special access attributes. | |
| These are normal strings, but with the special attributes: | |
| .l (or .list) : value as list (split on newlines). | |
| .n (or .nlstr): original value (the string itself). | |
| .s (or .spstr): value as whitespace-separated string. | |
| .p (or .paths): list of path objects (requires path.py package) | |
| Any values which require transformations are computed only once and | |
| cached. | |
| Such strings are very useful to efficiently interact with the shell, which | |
| typically only understands whitespace-separated options for commands.""" | |
| def get_list(self): | |
| try: | |
| return self.__list | |
| except AttributeError: | |
| self.__list = self.split('\n') | |
| return self.__list | |
| l = list = property(get_list) | |
| def get_spstr(self): | |
| try: | |
| return self.__spstr | |
| except AttributeError: | |
| self.__spstr = self.replace('\n',' ') | |
| return self.__spstr | |
| s = spstr = property(get_spstr) | |
| def get_nlstr(self): | |
| return self | |
| n = nlstr = property(get_nlstr) | |
| def get_paths(self): | |
| try: | |
| return self.__paths | |
| except AttributeError: | |
| self.__paths = [Path(p) for p in self.split('\n') if os.path.exists(p)] | |
| return self.__paths | |
| p = paths = property(get_paths) | |
| # FIXME: We need to reimplement type specific displayhook and then add this | |
| # back as a custom printer. This should also be moved outside utils into the | |
| # core. | |
| # def print_lsstring(arg): | |
| # """ Prettier (non-repr-like) and more informative printer for LSString """ | |
| # print "LSString (.p, .n, .l, .s available). Value:" | |
| # print arg | |
| # | |
| # | |
| # print_lsstring = result_display.register(LSString)(print_lsstring) | |
| class SList(list): | |
| """List derivative with a special access attributes. | |
| These are normal lists, but with the special attributes: | |
| * .l (or .list) : value as list (the list itself). | |
| * .n (or .nlstr): value as a string, joined on newlines. | |
| * .s (or .spstr): value as a string, joined on spaces. | |
| * .p (or .paths): list of path objects (requires path.py package) | |
| Any values which require transformations are computed only once and | |
| cached.""" | |
| def get_list(self): | |
| return self | |
| l = list = property(get_list) | |
| def get_spstr(self): | |
| try: | |
| return self.__spstr | |
| except AttributeError: | |
| self.__spstr = ' '.join(self) | |
| return self.__spstr | |
| s = spstr = property(get_spstr) | |
| def get_nlstr(self): | |
| try: | |
| return self.__nlstr | |
| except AttributeError: | |
| self.__nlstr = '\n'.join(self) | |
| return self.__nlstr | |
| n = nlstr = property(get_nlstr) | |
| def get_paths(self): | |
| try: | |
| return self.__paths | |
| except AttributeError: | |
| self.__paths = [Path(p) for p in self if os.path.exists(p)] | |
| return self.__paths | |
| p = paths = property(get_paths) | |
| def grep(self, pattern, prune = False, field = None): | |
| """ Return all strings matching 'pattern' (a regex or callable) | |
| This is case-insensitive. If prune is true, return all items | |
| NOT matching the pattern. | |
| If field is specified, the match must occur in the specified | |
| whitespace-separated field. | |
| Examples:: | |
| a.grep( lambda x: x.startswith('C') ) | |
| a.grep('Cha.*log', prune=1) | |
| a.grep('chm', field=-1) | |
| """ | |
| def match_target(s): | |
| if field is None: | |
| return s | |
| parts = s.split() | |
| try: | |
| tgt = parts[field] | |
| return tgt | |
| except IndexError: | |
| return "" | |
| if isinstance(pattern, str): | |
| pred = lambda x : re.search(pattern, x, re.IGNORECASE) | |
| else: | |
| pred = pattern | |
| if not prune: | |
| return SList([el for el in self if pred(match_target(el))]) | |
| else: | |
| return SList([el for el in self if not pred(match_target(el))]) | |
| def fields(self, *fields): | |
| """ Collect whitespace-separated fields from string list | |
| Allows quick awk-like usage of string lists. | |
| Example data (in var a, created by 'a = !ls -l'):: | |
| -rwxrwxrwx 1 ville None 18 Dec 14 2006 ChangeLog | |
| drwxrwxrwx+ 6 ville None 0 Oct 24 18:05 IPython | |
| * ``a.fields(0)`` is ``['-rwxrwxrwx', 'drwxrwxrwx+']`` | |
| * ``a.fields(1,0)`` is ``['1 -rwxrwxrwx', '6 drwxrwxrwx+']`` | |
| (note the joining by space). | |
| * ``a.fields(-1)`` is ``['ChangeLog', 'IPython']`` | |
| IndexErrors are ignored. | |
| Without args, fields() just split()'s the strings. | |
| """ | |
| if len(fields) == 0: | |
| return [el.split() for el in self] | |
| res = SList() | |
| for el in [f.split() for f in self]: | |
| lineparts = [] | |
| for fd in fields: | |
| try: | |
| lineparts.append(el[fd]) | |
| except IndexError: | |
| pass | |
| if lineparts: | |
| res.append(" ".join(lineparts)) | |
| return res | |
| def sort(self,field= None, nums = False): | |
| """ sort by specified fields (see fields()) | |
| Example:: | |
| a.sort(1, nums = True) | |
| Sorts a by second field, in numerical order (so that 21 > 3) | |
| """ | |
| #decorate, sort, undecorate | |
| if field is not None: | |
| dsu = [[SList([line]).fields(field), line] for line in self] | |
| else: | |
| dsu = [[line, line] for line in self] | |
| if nums: | |
| for i in range(len(dsu)): | |
| numstr = "".join([ch for ch in dsu[i][0] if ch.isdigit()]) | |
| try: | |
| n = int(numstr) | |
| except ValueError: | |
| n = 0 | |
| dsu[i][0] = n | |
| dsu.sort() | |
| return SList([t[1] for t in dsu]) | |
| # FIXME: We need to reimplement type specific displayhook and then add this | |
| # back as a custom printer. This should also be moved outside utils into the | |
| # core. | |
| # def print_slist(arg): | |
| # """ Prettier (non-repr-like) and more informative printer for SList """ | |
| # print "SList (.p, .n, .l, .s, .grep(), .fields(), sort() available):" | |
| # if hasattr(arg, 'hideonce') and arg.hideonce: | |
| # arg.hideonce = False | |
| # return | |
| # | |
| # nlprint(arg) # This was a nested list printer, now removed. | |
| # | |
| # print_slist = result_display.register(SList)(print_slist) | |
| def indent(instr,nspaces=4, ntabs=0, flatten=False): | |
| """Indent a string a given number of spaces or tabstops. | |
| indent(str,nspaces=4,ntabs=0) -> indent str by ntabs+nspaces. | |
| Parameters | |
| ---------- | |
| instr : basestring | |
| The string to be indented. | |
| nspaces : int (default: 4) | |
| The number of spaces to be indented. | |
| ntabs : int (default: 0) | |
| The number of tabs to be indented. | |
| flatten : bool (default: False) | |
| Whether to scrub existing indentation. If True, all lines will be | |
| aligned to the same indentation. If False, existing indentation will | |
| be strictly increased. | |
| Returns | |
| ------- | |
| str|unicode : string indented by ntabs and nspaces. | |
| """ | |
| if instr is None: | |
| return | |
| ind = '\t'*ntabs+' '*nspaces | |
| if flatten: | |
| pat = re.compile(r'^\s*', re.MULTILINE) | |
| else: | |
| pat = re.compile(r'^', re.MULTILINE) | |
| outstr = re.sub(pat, ind, instr) | |
| if outstr.endswith(os.linesep+ind): | |
| return outstr[:-len(ind)] | |
| else: | |
| return outstr | |
| def list_strings(arg): | |
| """Always return a list of strings, given a string or list of strings | |
| as input. | |
| Examples | |
| -------- | |
| :: | |
| In [7]: list_strings('A single string') | |
| Out[7]: ['A single string'] | |
| In [8]: list_strings(['A single string in a list']) | |
| Out[8]: ['A single string in a list'] | |
| In [9]: list_strings(['A','list','of','strings']) | |
| Out[9]: ['A', 'list', 'of', 'strings'] | |
| """ | |
| if isinstance(arg, str): | |
| return [arg] | |
| else: | |
| return arg | |
| def marquee(txt='',width=78,mark='*'): | |
| """Return the input string centered in a 'marquee'. | |
| Examples | |
| -------- | |
| :: | |
| In [16]: marquee('A test',40) | |
| Out[16]: '**************** A test ****************' | |
| In [17]: marquee('A test',40,'-') | |
| Out[17]: '---------------- A test ----------------' | |
| In [18]: marquee('A test',40,' ') | |
| Out[18]: ' A test ' | |
| """ | |
| if not txt: | |
| return (mark*width)[:width] | |
| nmark = (width-len(txt)-2)//len(mark)//2 | |
| if nmark < 0: nmark =0 | |
| marks = mark*nmark | |
| return '%s %s %s' % (marks,txt,marks) | |
| ini_spaces_re = re.compile(r'^(\s+)') | |
| def num_ini_spaces(strng): | |
| """Return the number of initial spaces in a string""" | |
| ini_spaces = ini_spaces_re.match(strng) | |
| if ini_spaces: | |
| return ini_spaces.end() | |
| else: | |
| return 0 | |
| def format_screen(strng): | |
| """Format a string for screen printing. | |
| This removes some latex-type format codes.""" | |
| # Paragraph continue | |
| par_re = re.compile(r'\\$',re.MULTILINE) | |
| strng = par_re.sub('',strng) | |
| return strng | |
| def dedent(text): | |
| """Equivalent of textwrap.dedent that ignores unindented first line. | |
| This means it will still dedent strings like: | |
| '''foo | |
| is a bar | |
| ''' | |
| For use in wrap_paragraphs. | |
| """ | |
| if text.startswith('\n'): | |
| # text starts with blank line, don't ignore the first line | |
| return textwrap.dedent(text) | |
| # split first line | |
| splits = text.split('\n',1) | |
| if len(splits) == 1: | |
| # only one line | |
| return textwrap.dedent(text) | |
| first, rest = splits | |
| # dedent everything but the first line | |
| rest = textwrap.dedent(rest) | |
| return '\n'.join([first, rest]) | |
| def wrap_paragraphs(text, ncols=80): | |
| """Wrap multiple paragraphs to fit a specified width. | |
| This is equivalent to textwrap.wrap, but with support for multiple | |
| paragraphs, as separated by empty lines. | |
| Returns | |
| ------- | |
| list of complete paragraphs, wrapped to fill `ncols` columns. | |
| """ | |
| paragraph_re = re.compile(r'\n(\s*\n)+', re.MULTILINE) | |
| text = dedent(text).strip() | |
| paragraphs = paragraph_re.split(text)[::2] # every other entry is space | |
| out_ps = [] | |
| indent_re = re.compile(r'\n\s+', re.MULTILINE) | |
| for p in paragraphs: | |
| # presume indentation that survives dedent is meaningful formatting, | |
| # so don't fill unless text is flush. | |
| if indent_re.search(p) is None: | |
| # wrap paragraph | |
| p = textwrap.fill(p, ncols) | |
| out_ps.append(p) | |
| return out_ps | |
| def strip_email_quotes(text): | |
| """Strip leading email quotation characters ('>'). | |
| Removes any combination of leading '>' interspersed with whitespace that | |
| appears *identically* in all lines of the input text. | |
| Parameters | |
| ---------- | |
| text : str | |
| Examples | |
| -------- | |
| Simple uses:: | |
| In [2]: strip_email_quotes('> > text') | |
| Out[2]: 'text' | |
| In [3]: strip_email_quotes('> > text\\n> > more') | |
| Out[3]: 'text\\nmore' | |
| Note how only the common prefix that appears in all lines is stripped:: | |
| In [4]: strip_email_quotes('> > text\\n> > more\\n> more...') | |
| Out[4]: '> text\\n> more\\nmore...' | |
| So if any line has no quote marks ('>'), then none are stripped from any | |
| of them :: | |
| In [5]: strip_email_quotes('> > text\\n> > more\\nlast different') | |
| Out[5]: '> > text\\n> > more\\nlast different' | |
| """ | |
| lines = text.splitlines() | |
| strip_len = 0 | |
| for characters in zip(*lines): | |
| # Check if all characters in this position are the same | |
| if len(set(characters)) > 1: | |
| break | |
| prefix_char = characters[0] | |
| if prefix_char in string.whitespace or prefix_char == ">": | |
| strip_len += 1 | |
| else: | |
| break | |
| text = "\n".join([ln[strip_len:] for ln in lines]) | |
| return text | |
| def strip_ansi(source): | |
| """ | |
| Remove ansi escape codes from text. | |
| Parameters | |
| ---------- | |
| source : str | |
| Source to remove the ansi from | |
| """ | |
| return re.sub(r'\033\[(\d|;)+?m', '', source) | |
| class EvalFormatter(Formatter): | |
| """A String Formatter that allows evaluation of simple expressions. | |
| Note that this version interprets a `:` as specifying a format string (as per | |
| standard string formatting), so if slicing is required, you must explicitly | |
| create a slice. | |
| This is to be used in templating cases, such as the parallel batch | |
| script templates, where simple arithmetic on arguments is useful. | |
| Examples | |
| -------- | |
| :: | |
| In [1]: f = EvalFormatter() | |
| In [2]: f.format('{n//4}', n=8) | |
| Out[2]: '2' | |
| In [3]: f.format("{greeting[slice(2,4)]}", greeting="Hello") | |
| Out[3]: 'll' | |
| """ | |
| def get_field(self, name, args, kwargs): | |
| v = eval(name, kwargs) | |
| return v, name | |
| #XXX: As of Python 3.4, the format string parsing no longer splits on a colon | |
| # inside [], so EvalFormatter can handle slicing. Once we only support 3.4 and | |
| # above, it should be possible to remove FullEvalFormatter. | |
| class FullEvalFormatter(Formatter): | |
| """A String Formatter that allows evaluation of simple expressions. | |
| Any time a format key is not found in the kwargs, | |
| it will be tried as an expression in the kwargs namespace. | |
| Note that this version allows slicing using [1:2], so you cannot specify | |
| a format string. Use :class:`EvalFormatter` to permit format strings. | |
| Examples | |
| -------- | |
| :: | |
| In [1]: f = FullEvalFormatter() | |
| In [2]: f.format('{n//4}', n=8) | |
| Out[2]: '2' | |
| In [3]: f.format('{list(range(5))[2:4]}') | |
| Out[3]: '[2, 3]' | |
| In [4]: f.format('{3*2}') | |
| Out[4]: '6' | |
| """ | |
| # copied from Formatter._vformat with minor changes to allow eval | |
| # and replace the format_spec code with slicing | |
| def vformat(self, format_string:str, args, kwargs)->str: | |
| result = [] | |
| for literal_text, field_name, format_spec, conversion in \ | |
| self.parse(format_string): | |
| # output the literal text | |
| if literal_text: | |
| result.append(literal_text) | |
| # if there's a field, output it | |
| if field_name is not None: | |
| # this is some markup, find the object and do | |
| # the formatting | |
| if format_spec: | |
| # override format spec, to allow slicing: | |
| field_name = ':'.join([field_name, format_spec]) | |
| # eval the contents of the field for the object | |
| # to be formatted | |
| obj = eval(field_name, kwargs) | |
| # do any conversion on the resulting object | |
| obj = self.convert_field(obj, conversion) | |
| # format the object and append to the result | |
| result.append(self.format_field(obj, '')) | |
| return ''.join(result) | |
| class DollarFormatter(FullEvalFormatter): | |
| """Formatter allowing Itpl style $foo replacement, for names and attribute | |
| access only. Standard {foo} replacement also works, and allows full | |
| evaluation of its arguments. | |
| Examples | |
| -------- | |
| :: | |
| In [1]: f = DollarFormatter() | |
| In [2]: f.format('{n//4}', n=8) | |
| Out[2]: '2' | |
| In [3]: f.format('23 * 76 is $result', result=23*76) | |
| Out[3]: '23 * 76 is 1748' | |
| In [4]: f.format('$a or {b}', a=1, b=2) | |
| Out[4]: '1 or 2' | |
| """ | |
| _dollar_pattern_ignore_single_quote = re.compile(r"(.*?)\$(\$?[\w\.]+)(?=([^']*'[^']*')*[^']*$)") | |
| def parse(self, fmt_string): | |
| for literal_txt, field_name, format_spec, conversion \ | |
| in Formatter.parse(self, fmt_string): | |
| # Find $foo patterns in the literal text. | |
| continue_from = 0 | |
| txt = "" | |
| for m in self._dollar_pattern_ignore_single_quote.finditer(literal_txt): | |
| new_txt, new_field = m.group(1,2) | |
| # $$foo --> $foo | |
| if new_field.startswith("$"): | |
| txt += new_txt + new_field | |
| else: | |
| yield (txt + new_txt, new_field, "", None) | |
| txt = "" | |
| continue_from = m.end() | |
| # Re-yield the {foo} style pattern | |
| yield (txt + literal_txt[continue_from:], field_name, format_spec, conversion) | |
| def __repr__(self): | |
| return "<DollarFormatter>" | |
| #----------------------------------------------------------------------------- | |
| # Utils to columnize a list of string | |
| #----------------------------------------------------------------------------- | |
| def _col_chunks(l, max_rows, row_first=False): | |
| """Yield successive max_rows-sized column chunks from l.""" | |
| if row_first: | |
| ncols = (len(l) // max_rows) + (len(l) % max_rows > 0) | |
| for i in range(ncols): | |
| yield [l[j] for j in range(i, len(l), ncols)] | |
| else: | |
| for i in range(0, len(l), max_rows): | |
| yield l[i:(i + max_rows)] | |
| def _find_optimal(rlist, row_first=False, separator_size=2, displaywidth=80): | |
| """Calculate optimal info to columnize a list of string""" | |
| for max_rows in range(1, len(rlist) + 1): | |
| col_widths = list(map(max, _col_chunks(rlist, max_rows, row_first))) | |
| sumlength = sum(col_widths) | |
| ncols = len(col_widths) | |
| if sumlength + separator_size * (ncols - 1) <= displaywidth: | |
| break | |
| return {'num_columns': ncols, | |
| 'optimal_separator_width': (displaywidth - sumlength) // (ncols - 1) if (ncols - 1) else 0, | |
| 'max_rows': max_rows, | |
| 'column_widths': col_widths | |
| } | |
| def _get_or_default(mylist, i, default=None): | |
| """return list item number, or default if don't exist""" | |
| if i >= len(mylist): | |
| return default | |
| else : | |
| return mylist[i] | |
| def compute_item_matrix(items, row_first=False, empty=None, *args, **kwargs) : | |
| """Returns a nested list, and info to columnize items | |
| Parameters | |
| ---------- | |
| items | |
| list of strings to columize | |
| row_first : (default False) | |
| Whether to compute columns for a row-first matrix instead of | |
| column-first (default). | |
| empty : (default None) | |
| default value to fill list if needed | |
| separator_size : int (default=2) | |
| How much characters will be used as a separation between each columns. | |
| displaywidth : int (default=80) | |
| The width of the area onto which the columns should enter | |
| Returns | |
| ------- | |
| strings_matrix | |
| nested list of string, the outer most list contains as many list as | |
| rows, the innermost lists have each as many element as columns. If the | |
| total number of elements in `items` does not equal the product of | |
| rows*columns, the last element of some lists are filled with `None`. | |
| dict_info | |
| some info to make columnize easier: | |
| num_columns | |
| number of columns | |
| max_rows | |
| maximum number of rows (final number may be less) | |
| column_widths | |
| list of with of each columns | |
| optimal_separator_width | |
| best separator width between columns | |
| Examples | |
| -------- | |
| :: | |
| In [1]: l = ['aaa','b','cc','d','eeeee','f','g','h','i','j','k','l'] | |
| In [2]: list, info = compute_item_matrix(l, displaywidth=12) | |
| In [3]: list | |
| Out[3]: [['aaa', 'f', 'k'], ['b', 'g', 'l'], ['cc', 'h', None], ['d', 'i', None], ['eeeee', 'j', None]] | |
| In [4]: ideal = {'num_columns': 3, 'column_widths': [5, 1, 1], 'optimal_separator_width': 2, 'max_rows': 5} | |
| In [5]: all((info[k] == ideal[k] for k in ideal.keys())) | |
| Out[5]: True | |
| """ | |
| info = _find_optimal(list(map(len, items)), row_first, *args, **kwargs) | |
| nrow, ncol = info['max_rows'], info['num_columns'] | |
| if row_first: | |
| return ([[_get_or_default(items, r * ncol + c, default=empty) for c in range(ncol)] for r in range(nrow)], info) | |
| else: | |
| return ([[_get_or_default(items, c * nrow + r, default=empty) for c in range(ncol)] for r in range(nrow)], info) | |
| def columnize(items, row_first=False, separator=" ", displaywidth=80, spread=False): | |
| """Transform a list of strings into a single string with columns. | |
| Parameters | |
| ---------- | |
| items : sequence of strings | |
| The strings to process. | |
| row_first : (default False) | |
| Whether to compute columns for a row-first matrix instead of | |
| column-first (default). | |
| separator : str, optional [default is two spaces] | |
| The string that separates columns. | |
| displaywidth : int, optional [default is 80] | |
| Width of the display in number of characters. | |
| Returns | |
| ------- | |
| The formatted string. | |
| """ | |
| if not items: | |
| return '\n' | |
| matrix, info = compute_item_matrix(items, row_first=row_first, separator_size=len(separator), displaywidth=displaywidth) | |
| if spread: | |
| separator = separator.ljust(int(info['optimal_separator_width'])) | |
| fmatrix = [filter(None, x) for x in matrix] | |
| sjoin = lambda x : separator.join([ y.ljust(w, ' ') for y, w in zip(x, info['column_widths'])]) | |
| return '\n'.join(map(sjoin, fmatrix))+'\n' | |
| def get_text_list(list_, last_sep=' and ', sep=", ", wrap_item_with=""): | |
| """ | |
| Return a string with a natural enumeration of items | |
| >>> get_text_list(['a', 'b', 'c', 'd']) | |
| 'a, b, c and d' | |
| >>> get_text_list(['a', 'b', 'c'], ' or ') | |
| 'a, b or c' | |
| >>> get_text_list(['a', 'b', 'c'], ', ') | |
| 'a, b, c' | |
| >>> get_text_list(['a', 'b'], ' or ') | |
| 'a or b' | |
| >>> get_text_list(['a']) | |
| 'a' | |
| >>> get_text_list([]) | |
| '' | |
| >>> get_text_list(['a', 'b'], wrap_item_with="`") | |
| '`a` and `b`' | |
| >>> get_text_list(['a', 'b', 'c', 'd'], " = ", sep=" + ") | |
| 'a + b + c = d' | |
| """ | |
| if len(list_) == 0: | |
| return '' | |
| if wrap_item_with: | |
| list_ = ['%s%s%s' % (wrap_item_with, item, wrap_item_with) for | |
| item in list_] | |
| if len(list_) == 1: | |
| return list_[0] | |
| return '%s%s%s' % ( | |
| sep.join(i for i in list_[:-1]), | |
| last_sep, list_[-1]) | |