Python：函数文档

有没有一种方法可以检查 python 本身内部的函数或方法的作用，类似于 Matlab 中的帮助函数。我想获得函数的定义，而不必谷歌它。

是的，您可以致电help(whatever)在Python交互式解释器中。

>>> help
Type help() for interactive help, or help(object) for help about object.

>>> help(zip)
Help on built-in function zip in module __builtin__:

zip(...)
    zip(seq1 [, seq2 [...]]) -> [(seq1[0], seq2[0] ...), (...)]

    Return a list of tuples, where each tuple contains the i-th element
    from each of the argument sequences.  The returned list is truncated
    in length to the length of the shortest argument sequence.

您甚至可以传递（引用的）关键字并获得非常详细的帮助：

>>> help('if')
The ``if`` statement
********************

The ``if`` statement is used for conditional execution:

   if_stmt ::= "if" expression ":" suite
               ( "elif" expression ":" suite )*
               ["else" ":" suite]

It selects exactly one of the suites by evaluating the expressions one
by one until one is found to be true (see section *Boolean operations*
for the definition of true and false); then that suite is executed
(and no other part of the ``if`` statement is executed or evaluated).
If all expressions are false, the suite of the ``else`` clause, if
present, is executed.

Related help topics: TRUTHVALUE

>>> help('def')
Function definitions
********************

A function definition defines a user-defined function object
....

甚至一般主题：

>>> help('FUNCTIONS')
Functions
*********

Function objects are created by function definitions.  The only
operation on a function object is to call it: ``func(argument-list)``.

There are really two flavors of function objects: built-in functions
and user-defined functions.  Both support the same operation (to call
the function), but the implementation is different, hence the
different object types.

See *Function definitions* for more information.

Related help topics: def, TYPES

• http://docs.python.org/2/library/functions.html#help

调用内置帮助系统。 （此函数用于交互式使用。）如果未给出参数，交互式帮助系统将在解释器控制台上启动。

如果参数是字符串，则将该字符串查找为模块、函数、类、方法、关键字或文档主题的名称，并在控制台上打印帮助页面。

如果参数是任何其他类型的对象，则会生成该对象的帮助页面。