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Contents | ---
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---
## Contents
- Introduction (node2.html#SECTION00200000000000000000)
- Notation (node3.html#SECTION00210000000000000000)
Lexical analysis (node4.html#SECTION00300000000000000000)
- Line structure (node5.html#SECTION00310000000000000000)
- Comments (node6.html#SECTION00311... | 1.2 | 4,932 | https://docs.python.org/{python_version}/python-ref/node1.html |
Indentation | ---
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## Indentation
Leading whitespace (spaces and tabs) at the beginning of a logical
line is used to compute the indentation level of the line, which in
turn is used to determine the grouping of statements.
First, tabs are replaced (from left to right) by on... | 1.2 | 2,367 | https://docs.python.org/{python_version}/python-ref/node10.html |
Other tokens | ---
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# Other tokens
Besides NEWLINE, INDENT and DEDENT, the following categories of tokens
exist: identifiers, keywords, literals, operators, and delimiters.
Spaces and tabs are not tokens, but serve to delimit tokens. Where
ambiguity exists, a token comprise... | 1.2 | 422 | https://docs.python.org/{python_version}/python-ref/node11.html |
Identifiers | ---
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# Identifiers
Identifiers (also referred to as names) are described by the following
lexical definitions:
```text
identifier: (letter|"_") (letter|digit|"_")*
letter: lowercase | uppercase
lowercase: "a"..."z"
uppercase: "A"..."Z"
digit: "0"..."9"
```
Id... | 1.2 | 449 | https://docs.python.org/{python_version}/python-ref/node12.html |
Keywords | ---
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## Keywords
The following identifiers are used as reserved words, or
keywords of the language, and cannot be used as ordinary
identifiers. They must be spelled exactly as written here:
```text
access del from lambda return
and elif global not try
break ... | 1.2 | 425 | https://docs.python.org/{python_version}/python-ref/node13.html |
Literals | ---
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# Literals
Literals are notations for constant values of some built-in types.
---
- String literals (node15.html#SECTION00341000000000000000)
Numeric literals (node16.html#SECTION00342000000000000000)
---
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String literals | ---
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## String literals
String literals are described by the following lexical definitions:
```text
stringliteral: shortstring | longstring
shortstring: "'" shortstringitem* "'" | '"' shortstringitem* '"'
longstring: "'''" longstringitem* "'''" | '"""' longs... | 1.2 | 1,622 | https://docs.python.org/{python_version}/python-ref/node15.html |
Numeric literals | ---
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## Numeric literals
There are three types of numeric literals: plain integers, long
integers, and floating point numbers.
Integer and long integer literals are described by the following
lexical definitions:
```text
longinteger: integer ("l"|"L")
intege... | 1.2 | 1,879 | https://docs.python.org/{python_version}/python-ref/node16.html |
Operators | ---
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# Operators
The following tokens are operators:
```text
+ - * / %
<< >> & | ^ ~
< == > <= <> != >=
```
The comparison operators `<>` and `!=` are alternate
spellings of the same operator.
---
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Delimiters | ---
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# Delimiters
The following tokens serve as delimiters or otherwise have a special
meaning:
```text
( ) [ ] { }
, : . " ` '
= ;
```
The following printing ASCII characters are not used in Python. Their
occurrence outside string literals and comments is an... | 1.2 | 436 | https://docs.python.org/{python_version}/python-ref/node18.html |
Data model | ---
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# Data model
---
- Objects, values and types (node20.html#SECTION00410000000000000000)
The standard type hierarchy (node21.html#SECTION00420000000000000000)
Special method names (node22.html#SECTION00430000000000000000)
- Special methods for any type (node... | 1.2 | 694 | https://docs.python.org/{python_version}/python-ref/node19.html |
Introduction | ---
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---
# Introduction
This reference manual describes the Python programming language.
It is not intended as a tutorial.
While I am trying to be as precise as possible, I chose to use English
rather than formal specifications for everything except syntax and
lexica... | 1.2 | 1,650 | https://docs.python.org/{python_version}/python-ref/node2.html |
Objects, values and types | ---
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# Objects, values and types
Objects are Python's abstraction for data. All data in a Python
program is represented by objects or by relations between objects.
(In a sense, and in conformance to Von Neumann's model of a
``stored program computer'', code ... | 1.2 | 3,219 | https://docs.python.org/{python_version}/python-ref/node20.html |
The standard type hierarchy | ---
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# The standard type hierarchy
Below is a list of the types that are built into Python. Extension
modules written in C can define additional types. Future versions of
Python may add types to the type hierarchy (e.g. rational or complex
numbers, efficient... | 1.2 | 930 | https://docs.python.org/{python_version}/python-ref/node21.html |
Special method names | ---
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# Special method names
A class can implement certain operations that are invoked by special
syntax (such as subscription or arithmetic operations) by defining
methods with special names. For instance, if a class defines a
method named `__getitem__`, and... | 1.2 | 1,277 | https://docs.python.org/{python_version}/python-ref/node22.html |
Special methods for any type | ---
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## Special methods for any type
---
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---
---
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Special methods for attribute access | ---
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## Special methods for attribute access
The following methods can be used to change the meaning of attribute
access for class instances.
---
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Special methods for sequence and mapping types | ---
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## Special methods for sequence and mapping types
---
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Special methods for sequence types | ---
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## Special methods for sequence types
---
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Special methods for numeric types | ---
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## Special methods for numeric types
---
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---
---
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Execution model | ---
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# Execution model
---
- Code blocks, execution frames, and name spaces (node29.html#SECTION00510000000000000000)
Exceptions (node30.html#SECTION00520000000000000000)
---
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Code blocks, execution frames, and name spaces | ---
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# Code blocks, execution frames, and name spaces
A code block is a piece of Python program text that can be
executed as a unit, such as a module, a class definition or a function
body. Some code blocks (like modules) are executed only once, others
(like... | 1.2 | 3,709 | https://docs.python.org/{python_version}/python-ref/node29.html |
Notation | ---
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# Notation
The descriptions of lexical analysis and syntax use a modified BNF
grammar notation. This uses the following style of definition:
```text
name: lc_letter (lc_letter | "_")*
lc_letter: "a"..."z"
```
The first line says that a `name` is an `lc_let... | 1.2 | 2,279 | https://docs.python.org/{python_version}/python-ref/node3.html |
Exceptions | ---
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# Exceptions
Exceptions are a means of breaking out of the normal flow of control
of a code block in order to handle errors or other exceptional
conditions. An exception is raised at the point where the error
is detected; it may be handled by the surrou... | 1.2 | 1,563 | https://docs.python.org/{python_version}/python-ref/node30.html |
Expressions and conditions | ---
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# Expressions and conditions
Note: In this and the following chapters, extended BNF notation
will be used to describe syntax, not lexical analysis.
This chapter explains the meaning of the elements of expressions and
conditions. Conditions are a superset o... | 1.2 | 2,431 | https://docs.python.org/{python_version}/python-ref/node31.html |
Arithmetic conversions | ---
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# Arithmetic conversions
When a description of an arithmetic operator below uses the phrase
``the numeric arguments are converted to a common type'',
this both means that if either argument is not a number, a
`TypeError` exception is raised, and that ot... | 1.2 | 636 | https://docs.python.org/{python_version}/python-ref/node32.html |
Atoms | ---
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# Atoms
Atoms are the most basic elements of expressions. Forms enclosed in
reverse quotes or in parentheses, brackets or braces are also
categorized syntactically as atoms. The syntax for atoms is:
```text
atom: identifier | literal | enclosure
enclosu... | 1.2 | 767 | https://docs.python.org/{python_version}/python-ref/node33.html |
Identifiers (Names) | ---
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---
## Identifiers (Names)
An identifier occurring as an atom is a reference to a local, global
or built-in name binding. If a name is assigned to anywhere in a code
block (even in unreachable code), and is not mentioned in a
`global` statement in that code... | 1.2 | 804 | https://docs.python.org/{python_version}/python-ref/node34.html |
Literals | ---
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---
## Literals
Python knows string and numeric literals:
```text
literal: stringliteral | integer | longinteger | floatnumber
```
Evaluation of a literal yields an object of the given type (string,
integer, long integer, floating point number) with the giv... | 1.2 | 897 | https://docs.python.org/{python_version}/python-ref/node35.html |
Parenthesized forms | ---
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## Parenthesized forms
A parenthesized form is an optional condition list enclosed in
parentheses:
```text
parenth_form: "(" [condition_list] ")"
```
A parenthesized condition list yields whatever that condition list
yields.
An empty pair of parentheses... | 1.2 | 715 | https://docs.python.org/{python_version}/python-ref/node36.html |
List displays | ---
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## List displays
A list display is a possibly empty series of conditions enclosed in
square brackets:
```text
list_display: "[" [condition_list] "]"
```
A list display yields a new list object.
If it has no condition list, the list object has no items. ... | 1.2 | 462 | https://docs.python.org/{python_version}/python-ref/node37.html |
Dictionary displays | ---
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## Dictionary displays
A dictionary display is a possibly empty series of key/datum pairs
enclosed in curly braces:
```text
dict_display: "{" [key_datum_list] "}"
key_datum_list: key_datum ("," key_datum)* [","]
key_datum: condition ":" condition
```
A ... | 1.2 | 801 | https://docs.python.org/{python_version}/python-ref/node38.html |
String conversions | ---
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---
## String conversions
A string conversion is a condition list enclosed in reverse (or
backward) quotes:
```text
string_conversion: "`" condition_list "`"
```
A string conversion evaluates the contained condition list and
converts the resulting object in... | 1.2 | 1,219 | https://docs.python.org/{python_version}/python-ref/node39.html |
Lexical analysis | ---
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# Lexical analysis
A Python program is read by a parser. Input to the parser is a
stream of tokens, generated by the lexical analyzer. This
chapter describes how the lexical analyzer breaks a file into tokens.
---
- Line structure (node5.html#SECTION00310000... | 1.2 | 1,072 | https://docs.python.org/{python_version}/python-ref/node4.html |
Primaries | ---
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# Primaries
Primaries represent the most tightly bound operations of the language.
Their syntax is:
```text
primary: atom | attributeref | subscription | slicing | call
```
---
- Attribute references (node41.html#SECTION00631000000000000000)
Subscriptio... | 1.2 | 480 | https://docs.python.org/{python_version}/python-ref/node40.html |
Attribute references | ---
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## Attribute references
An attribute reference is a primary followed by a period and a name:
```text
attributeref: primary "." identifier
```
The primary must evaluate to an object of a type that supports
attribute references, e.g. a module or a list. T... | 1.2 | 658 | https://docs.python.org/{python_version}/python-ref/node41.html |
Subscriptions | ---
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---
## Subscriptions
A subscription selects an item of a sequence (string, tuple or list)
or mapping (dictionary) object:
```text
subscription: primary "[" condition "]"
```
The primary must evaluate to an object of a sequence or mapping type.
If it is a ma... | 1.2 | 1,005 | https://docs.python.org/{python_version}/python-ref/node42.html |
Slicings | ---
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## Slicings
A slicing (or slice) selects a range of items in a sequence (string,
tuple or list) object:
```text
slicing: primary "[" [condition] ":" [condition] "]"
```
The primary must evaluate to a sequence object. The lower and upper
bound expression... | 1.2 | 785 | https://docs.python.org/{python_version}/python-ref/node43.html |
Calls | ---
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## Calls
A call calls a callable object (e.g. a function) with a possibly empty
series of arguments:
```text
call: primary "(" [condition_list] ")"
```
The primary must evaluate to a callable object (user-defined
functions, built-in functions, methods o... | 1.2 | 671 | https://docs.python.org/{python_version}/python-ref/node44.html |
Unary arithmetic operations | ---
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# Unary arithmetic operations
All unary arithmetic (and bit-wise) operations have the same priority:
```text
u_expr: primary | "-" u_expr | "+" u_expr | "~" u_expr
```
The unary `"-"` (minus) operator yields the negation of its
numeric argument.
The una... | 1.2 | 659 | https://docs.python.org/{python_version}/python-ref/node45.html |
Binary arithmetic operations | ---
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# Binary arithmetic operations
The binary arithmetic operations have the conventional priority
levels. Note that some of these operations also apply to certain
non-numeric types. There is no ``power'' operator, so there are only
two levels, one for mult... | 1.2 | 2,581 | https://docs.python.org/{python_version}/python-ref/node46.html |
Shifting operations | ---
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# Shifting operations
The shifting operations have lower priority than the arithmetic
operations:
```text
shift_expr: a_expr | shift_expr ( "<<" | ">>" ) a_expr
```
These operators accept plain or long integers as arguments. The
arguments are converted ... | 1.2 | 792 | https://docs.python.org/{python_version}/python-ref/node47.html |
Binary bit-wise operations | ---
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# Binary bit-wise operations
Each of the three bitwise operations has a different priority level:
```text
and_expr: shift_expr | and_expr "&" shift_expr
xor_expr: and_expr | xor_expr "^" and_expr
or_expr: xor_expr | or_expr "|" xor_expr
```
The `"&"` op... | 1.2 | 782 | https://docs.python.org/{python_version}/python-ref/node48.html |
Comparisons | ---
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# Comparisons
Contrary to C, all comparison operations in Python have the same
priority, which is lower than that of any arithmetic, shifting or
bitwise operation. Also contrary to C, expressions like
`a < b < c` have the interpretation that is conventi... | 1.2 | 2,968 | https://docs.python.org/{python_version}/python-ref/node49.html |
Line structure | ---
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# Line structure
A Python program is divided in a number of logical lines. The end of
a logical line is represented by the token NEWLINE. Statements cannot
cross logical line boundaries except where NEWLINE is allowed by the
syntax (e.g. between statements... | 1.2 | 651 | https://docs.python.org/{python_version}/python-ref/node5.html |
Boolean operations | ---
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# Boolean operations
Boolean operations have the lowest priority of all Python operations:
```text
condition: or_test | lambda_form
or_test: and_test | or_test "or" and_test
and_test: not_test | and_test "and" not_test
not_test: comparison | "not" not_t... | 1.2 | 1,940 | https://docs.python.org/{python_version}/python-ref/node50.html |
Expression lists and condition lists | ---
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# Expression lists and condition lists
```text
expr_list: or_expr ("," or_expr)* [","]
cond_list: condition ("," condition)* [","]
```
The only difference between expression lists and condition lists is
the lowest priority of operators that can be used ... | 1.2 | 1,380 | https://docs.python.org/{python_version}/python-ref/node51.html |
Summary | ---
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# Summary
The following table summarizes the operator precedences in Python,
from lowest precedence (least binding) to highest precedence (most
binding). Operators in the same box have the same precedence. Unless
the syntax is explicitly given, operator... | 1.2 | 468 | https://docs.python.org/{python_version}/python-ref/node52.html |
Simple statements | ---
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# Simple statements
Simple statements are comprised within a single logical line.
Several simple statements may occur on a single line separated
by semicolons. The syntax for simple statements is:
```text
simple_stmt: expression_stmt
| assignment_stmt
| pa... | 1.2 | 1,305 | https://docs.python.org/{python_version}/python-ref/node53.html |
Expression statements | ---
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---
# Expression statements
Expression statements are used (mostly interactively) to compute and
write a value, or (usually) to call a procedure (a function that
returns no meaningful result; in Python, procedures return the value
`None`):
```text
expressio... | 1.2 | 878 | https://docs.python.org/{python_version}/python-ref/node54.html |
Assignment statements | ---
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# Assignment statements
Assignment statements are used to (re)bind names to values and to
modify attributes or items of mutable objects:
```text
assignment_stmt: (target_list "=")+ expression_list
target_list: target ("," target)* [","]
target: identifi... | 1.2 | 2,304 | https://docs.python.org/{python_version}/python-ref/node55.html |
The pass statement | ---
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---
# The pass statement
```text
pass_stmt: "pass"
```
`pass` is a null operation --- when it is executed, nothing
happens. It is useful as a placeholder when a statement is
required syntactically, but no code needs to be executed, for example:
```text
def ... | 1.2 | 438 | https://docs.python.org/{python_version}/python-ref/node56.html |
The del statement | ---
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---
# The del statement
```text
del_stmt: "del" target_list
```
Deletion is recursively defined very similar to the way assignment is
defined. Rather that spelling it out in full details, here are some
hints.
Deletion of a target list recursively deletes ea... | 1.2 | 812 | https://docs.python.org/{python_version}/python-ref/node57.html |
The print statement | ---
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---
# The print statement
```text
print_stmt: "print" [ condition ("," condition)* [","] ]
```
`print` evaluates each condition in turn and writes the resulting
object to standard output (see below). If an object is not a string,
it is first converted to a ... | 1.2 | 1,408 | https://docs.python.org/{python_version}/python-ref/node58.html |
The return statement | ---
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---
# The return statement
```text
return_stmt: "return" [condition_list]
```
`return` may only occur syntactically nested in a function
definition, not within a nested class definition.
If a condition list is present, it is evaluated, else `None`
is substi... | 1.2 | 585 | https://docs.python.org/{python_version}/python-ref/node59.html |
Comments | ---
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---
## Comments
A comment starts with a hash character (`#`) that is not part of
a string literal, and ends at the end of the physical line. A comment
always signifies the end of the logical line. Comments are ignored by
the syntax.
---
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The raise statement | ---
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---
# The raise statement
```text
raise_stmt: "raise" condition ["," condition]
```
`raise` evaluates its first condition, which must yield
a string, class, or instance object. If there is a second condition,
this is evaluated, else `None` is substituted. I... | 1.2 | 835 | https://docs.python.org/{python_version}/python-ref/node60.html |
The break statement | ---
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---
# The break statement
```text
break_stmt: "break"
```
`break` may only occur syntactically nested in a `for`
or `while` loop, but not nested in a function or class definition
within that loop.
It terminates the nearest enclosing loop, skipping the optio... | 1.2 | 608 | https://docs.python.org/{python_version}/python-ref/node61.html |
The continue statement | ---
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---
# The continue statement
```text
continue_stmt: "continue"
```
`continue` may only occur syntactically nested in a `for` or
`while` loop, but not nested in a function or class definition or
`try` statement within that loop.footnode.html#1125
It continue... | 1.2 | 389 | https://docs.python.org/{python_version}/python-ref/node62.html |
The import statement | ---
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---
# The import statement
```text
import_stmt: "import" identifier ("," identifier)*
| "from" identifier "import" identifier ("," identifier)*
| "from" identifier "import" "*"
```
Import statements are executed in two steps: (1) find a module, and
initiali... | 1.2 | 2,889 | https://docs.python.org/{python_version}/python-ref/node63.html |
The global statement | ---
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---
# The global statement
```text
global_stmt: "global" identifier ("," identifier)*
```
The `global` statement is a declaration which holds for the
entire current scope. It means that the listed identifiers are to be
interpreted as globals. While using gl... | 1.2 | 970 | https://docs.python.org/{python_version}/python-ref/node64.html |
The access statement | ---
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---
# The access statement
```text
access_stmt: "access" ...
```
This statement will be used in the future to control access to
instance and class variables. Currently its syntax and effects are
undefined; however the keyword `access` is a reserved word for... | 1.2 | 349 | https://docs.python.org/{python_version}/python-ref/node65.html |
The exec statement | ---
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---
# The exec statement
```text
exec_stmt: "exec" expression ["in" expression ["," expression]]
```
This statement supports dynamic execution of Python code. The first
expression should evaluate to either a string, an open file object, or
a code object. If... | 1.2 | 1,147 | https://docs.python.org/{python_version}/python-ref/node66.html |
Compound statements | ---
node68.html ref.html node66.html node1.html node79.html
---
# Compound statements
Compound statements contain (groups of) other statements; they affect
or control the execution of those other statements in some way. In
general, compound statements span multiple lines, although in simple
incarnations a whole compoun... | 1.2 | 2,723 | https://docs.python.org/{python_version}/python-ref/node67.html |
The if statement | ---
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---
# The if statement
The `if` statement is used for conditional execution:
```text
if_stmt: "if" condition ":" suite
("elif" condition ":" suite)*
["else" ":" suite]
```
It selects exactly one of the suites by evaluating the conditions one
by one until on... | 1.2 | 613 | https://docs.python.org/{python_version}/python-ref/node68.html |
The while statement | ---
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---
# The while statement
The `while` statement is used for repeated execution as long as a
condition is true:
```text
while_stmt: "while" condition ":" suite
["else" ":" suite]
```
This repeatedly tests the condition and, if it is true, executes the
first ... | 1.2 | 725 | https://docs.python.org/{python_version}/python-ref/node69.html |
Explicit line joining | ---
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---
## Explicit line joining
Two or more physical lines may be joined into logical lines using
backslash characters (`\`), as follows: when a physical line ends
in a backslash that is not part of a string literal or comment, it is
joined with the following for... | 1.2 | 761 | https://docs.python.org/{python_version}/python-ref/node7.html |
The for statement | ---
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---
# The for statement
The `for` statement is used to iterate over the elements of a
sequence (string, tuple or list):
```text
for_stmt: "for" target_list "in" condition_list ":" suite
["else" ":" suite]
```
The condition list is evaluated once; it should ... | 1.2 | 2,355 | https://docs.python.org/{python_version}/python-ref/node70.html |
The try statement | ---
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---
# The try statement
The `try` statement specifies exception handlers and/or cleanup
code for a group of statements:
```text
try_stmt: try_exc_stmt | try_fin_stmt
try_exc_stmt: "try" ":" suite
("except" [condition ["," target]] ":" suite)+
["else" ":" su... | 1.2 | 3,751 | https://docs.python.org/{python_version}/python-ref/node71.html |
Function definitions | ---
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---
# Function definitions
A function definition defines a user-defined function object (see
section node21.html#types):
```text
funcdef: "def" funcname "(" [parameter_list] ")" ":" suite
parameter_list: (defparameter ",")* ("*" identifier | defparameter ["... | 1.2 | 3,795 | https://docs.python.org/{python_version}/python-ref/node72.html |
Class definitions | ---
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---
# Class definitions
A class definition defines a class object (see section node21.html#types):
```text
classdef: "class" classname [inheritance] ":" suite
inheritance: "(" [condition_list] ")"
classname: identifier
```
A class definition is an executabl... | 1.2 | 1,031 | https://docs.python.org/{python_version}/python-ref/node73.html |
Top-level components | ---
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---
# Top-level components
The Python interpreter can get its input from a number of sources:
from a script passed to it as standard input or as program argument,
typed in interactively, from a module source file, etc. This chapter
gives the syntax used in the... | 1.2 | 591 | https://docs.python.org/{python_version}/python-ref/node74.html |
Complete Python programs | ---
node76.html node74.html node74.html node1.html node79.html
---
# Complete Python programs
While a language specification need not prescribe how the language
interpreter is invoked, it is useful to have a notion of a complete
Python program. A complete Python program is executed in a minimally
initialized environmen... | 1.2 | 1,388 | https://docs.python.org/{python_version}/python-ref/node75.html |
File input | ---
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---
# File input
All input read from non-interactive files has the same form:
```text
file_input: (NEWLINE | statement)*
```
This syntax is used in the following situations:
- when parsing a complete Python program (from a file or from a string);
when parsi... | 1.2 | 403 | https://docs.python.org/{python_version}/python-ref/node76.html |
Interactive input | ---
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---
# Interactive input
Input in interactive mode is parsed using the following grammar:
```text
interactive_input: [stmt_list] NEWLINE | compound_stmt NEWLINE
```
Note that a (top-level) compound statement must be followed by a blank
line in interactive mo... | 1.2 | 403 | https://docs.python.org/{python_version}/python-ref/node77.html |
Expression input | ---
node79.html node74.html node77.html node1.html node79.html
---
# Expression input
There are two forms of expression input. Both ignore leading
whitespace.
The string argument to `eval()` must have the following form:
```text
eval_input: condition_list NEWLINE*
```
The input line read by `input()` must have the foll... | 1.2 | 543 | https://docs.python.org/{python_version}/python-ref/node78.html |
Index | ---
node80.html ref.html node78.html node1.html
---
## Index
---
guido@cwi.nl | 1.2 | 77 | https://docs.python.org/{python_version}/python-ref/node79.html |
Implicit line joining | ---
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---
## Implicit line joining
Expressions in parentheses, square brackets or curly braces can be
split over more than one physical line without using backslashes.
For example:
```text
month_names = ['Januari', 'Februari', 'Maart', # These are the
'April', 'Mei'... | 1.2 | 608 | https://docs.python.org/{python_version}/python-ref/node8.html |
About this document ... | ---
ref.html node79.html node1.html node79.html
---
# About this document ...
Python Reference Manual
This document was generated using the LaTeX2HTML (http://cbl.leeds.ac.uk/nikos/tex2html/doc/latex2html/latex2html.html) translator Version 95.1 (Fri Jan 20 1995) Copyright © 1993, 1994, Nikos Drakos (http://cbl.leeds.a... | 1.2 | 594 | https://docs.python.org/{python_version}/python-ref/node80.html |
Blank lines | ---
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---
## Blank lines
A logical line that contains only spaces, tabs, and possibly a
comment, is ignored (i.e., no NEWLINE token is generated), except that
during interactive input of statements, an entirely blank logical line
terminates a multi-line statement.
... | 1.2 | 336 | https://docs.python.org/{python_version}/python-ref/node9.html |
Python Reference Manual | ---
node1.html node1.html node79.html
---
# Python Reference Manual
Guido van Rossum
Dept. AA, CWI, P.O. Box 94079
1090 GB Amsterdam, The Netherlands
E-mail: guido@cwi.nl
10 April 1995
Release 1.2
Copyright © 1991-1995 by Stichting Mathematisch Centrum,
Amsterdam, The Netherlands.
All Rights Reserved
Permission to use,... | 1.2 | 7,344 | https://docs.python.org/{python_version}/python-ref/ref.html |
Footnotes | guido@cwi.nl | 1.2 | 12 | https://docs.python.org/{python_version}/python-tut/footnode.html |
Contents | ---
node2.html tut.html tut.html
---
## Contents
- Whetting Your Appetite (node2.html#SECTION00200000000000000000)
- Where From Here (node3.html#SECTION00210000000000000000)
Using the Python Interpreter (node4.html#SECTION00300000000000000000)
- Invoking the Interpreter (node5.html#SECTION00310000000000000000)
- Argume... | 1.2 | 6,590 | https://docs.python.org/{python_version}/python-tut/node1.html |
The Module Search Path | ---
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---
## The Module Search Path
When a module named spam is imported, the interpreter searches
for a file named spam.py in the list of directories specified by
the environment variable PYTHONPATH. It has the same syntax as
the Unix shell variable PATH, i.e., a list of colo... | 1.2 | 838 | https://docs.python.org/{python_version}/python-tut/node10.html |
Python and the World-Wide Web | ---
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---
# Python and the World-Wide Web
There is a growing number of modules available for writing WWW tools.
The previous release already sported modules `gopherlib`,
`ftplib`, `httplib` and `urllib` (which unifies the
other three) for accessing data through the commones... | 1.2 | 1,103 | https://docs.python.org/{python_version}/python-tut/node100.html |
Miscellaneous | ---
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---
# Miscellaneous
- The `socket` module now exports all the needed constants used for
socket operations, such as `SO_BROADCAST`.
The functions `popen()` and `fdopen()` in the `os`
module now follow the pattern of the built-in function `open()`:
the default mode arg... | 1.2 | 524 | https://docs.python.org/{python_version}/python-tut/node101.html |
About this document ... | ---
tut.html node101.html node1.html
---
# About this document ...
Python Tutorial
This document was generated using the LaTeX2HTML (http://cbl.leeds.ac.uk/nikos/tex2html/doc/latex2html/latex2html.html) translator Version 95.1 (Fri Jan 20 1995) Copyright © 1993, 1994, Nikos Drakos (http://cbl.leeds.ac.uk/nikos/personal... | 1.2 | 575 | https://docs.python.org/{python_version}/python-tut/node102.html |
``Compiled'' Python files | ---
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---
## ``Compiled'' Python files
As an important speed-up of the start-up time for short programs that
use a lot of standard modules, if a file called spam.pyc exists
in the directory where spam.py is found, this is assumed to
contain an already-``compiled'' version of ... | 1.2 | 779 | https://docs.python.org/{python_version}/python-tut/node11.html |
Executable Python scripts | ---
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---
## Executable Python scripts
On BSD'ish Unix systems, Python scripts can be made directly
executable, like shell scripts, by putting the line
```text
#! /usr/local/bin/python
```
(assuming that's the name of the interpreter) at the beginning of the
script and giving... | 1.2 | 419 | https://docs.python.org/{python_version}/python-tut/node12.html |
The Interactive Startup File | ---
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---
## The Interactive Startup File
When you use Python interactively, it is frequently handy to have some
standard commands executed every time the interpreter is started. You
can do this by setting an environment variable named
PYTHONSTARTUP to the name of a file cont... | 1.2 | 1,202 | https://docs.python.org/{python_version}/python-tut/node13.html |
Interactive Input Editing and History Substitution | ---
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---
# Interactive Input Editing and History Substitution
Some versions of the Python interpreter support editing of the current
input line and history substitution, similar to facilities found in
the Korn shell and the GNU Bash shell. This is implemented using the
GNU R... | 1.2 | 1,012 | https://docs.python.org/{python_version}/python-tut/node14.html |
Line Editing | ---
node16.html node14.html node14.html node1.html
---
## Line Editing
If supported, input line editing is active whenever the interpreter
prints a primary or secondary prompt. The current line can be edited
using the conventional Emacs control characters. The most important
of these are: C-A (Control-A) moves the curs... | 1.2 | 727 | https://docs.python.org/{python_version}/python-tut/node15.html |
History Substitution | ---
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---
## History Substitution
History substitution works as follows. All non-empty input lines
issued are saved in a history buffer, and when a new prompt is given
you are positioned on a new line at the bottom of this buffer. C-P
moves one line up (back) in the history ... | 1.2 | 620 | https://docs.python.org/{python_version}/python-tut/node16.html |
Key Bindings | ---
node18.html node14.html node16.html node1.html
---
## Key Bindings
The key bindings and some other parameters of the Readline library can
be customized by placing commands in an initialization file called
$HOME/.inputrc. Key bindings have the form
```text
key-name: function-name
```
or
```text
"string": function-na... | 1.2 | 937 | https://docs.python.org/{python_version}/python-tut/node17.html |
Commentary | ---
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---
## Commentary
This facility is an enormous step forward compared to previous
versions of the interpreter; however, some wishes are left: It would
be nice if the proper indentation were suggested on continuation lines
(the parser knows if an indent token is required... | 1.2 | 504 | https://docs.python.org/{python_version}/python-tut/node18.html |
An Informal Introduction to Python | ---
node20.html tut.html node18.html node1.html
---
# An Informal Introduction to Python
In the following examples, input and output are distinguished by the
presence or absence of prompts (>>> and ...): to repeat
the example, you must type everything after the prompt, when the
prompt appears; lines that do not begin w... | 1.2 | 840 | https://docs.python.org/{python_version}/python-tut/node19.html |
Whetting Your Appetite | ---
node3.html tut.html node1.html node1.html
---
# Whetting Your Appetite
If you ever wrote a large shell script, you probably know this
feeling: you'd love to add yet another feature, but it's already so
slow, and so big, and so complicated; or the feature involves a system
call or other function that is only accessi... | 1.2 | 3,190 | https://docs.python.org/{python_version}/python-tut/node2.html |
Using Python as a Calculator | ---
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---
# Using Python as a Calculator
Let's try some simple Python commands. Start the interpreter and wait
for the primary prompt, >>>. (It shouldn't take long.)
---
- Numbers (node21.html#SECTION00411000000000000000)
Strings (node22.html#SECTION00412000000000000000)
Lis... | 1.2 | 381 | https://docs.python.org/{python_version}/python-tut/node20.html |
Numbers | ---
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---
## Numbers
The interpreter acts as a simple calculator: you can type an
expression at it and it will write the value. Expression syntax is
straightforward: the operators +, -, * and /
work just like in most other languages (e.g., Pascal or C); parentheses
can be us... | 1.2 | 1,067 | https://docs.python.org/{python_version}/python-tut/node21.html |
Strings | ---
node23.html node20.html node21.html node1.html
---
## Strings
Besides numbers, Python can also manipulate strings, enclosed in
single quotes or double quotes:
```text
>>> 'spam eggs'
'spam eggs'
>>> 'doesn\'t'
"doesn't"
>>> "doesn't"
"doesn't"
>>> '"Yes," he said.'
'"Yes," he said.'
>>> "\"Yes,\" he said."
'"Yes," ... | 1.2 | 3,638 | https://docs.python.org/{python_version}/python-tut/node22.html |
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