【Python】【基础知识】【内置函数】【help的使用方法】

原英文帮助文档：

help([object])

Invoke the built-in help system. (This function is intended for interactive use.) If no argument is given, the interactive help system starts on the interpreter console. If the argument is a string, then the string is looked up as the name of a module, function, class, method, keyword, or documentation topic, and a help page is printed on the console. If the argument is any other kind of object, a help page on the object is generated.

This function is added to the built-in namespace by the site module.

Changed in version 3.4: Changes to pydoc and inspect mean that the reported signatures for callables are now more comprehensive and consistent.

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中文解释

调用内置的帮助系统。（这个函数用于交互模式使用）

如果未给出参数，则交互帮助系统将在解释器控制台上启动。

示例：

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

Welcome to Python 3.7's help utility!

If this is your first time using Python, you should definitely check out
the tutorial on the Internet at https://docs.python.org/3.7/tutorial/.

Enter the name of any module, keyword, or topic to get help on writing
Python programs and using Python modules.  To quit this help utility and
return to the interpreter, just type "quit".

To get a list of available modules, keywords, symbols, or topics, type
"modules", "keywords", "symbols", or "topics".  Each module also comes
with a one-line summary of what it does; to list the modules whose name
or summary contain a given string such as "spam", type "modules spam".

help> abs
Help on built-in function abs in module builtins:

abs(x, /)
    Return the absolute value of the argument.

help> input
Help on built-in function input in module builtins:

input(prompt=None, /)
    Read a string from standard input.  The trailing newline is stripped.

    The prompt string, if given, is printed to standard output without a
    trailing newline before reading input.

    If the user hits EOF (*nix: Ctrl-D, Windows: Ctrl-Z+Return), raise EOFError.
    On *nix systems, readline is used if available.

help> input()
No Python documentation found for 'input()'.
Use help() to get the interactive help utility.
Use help(str) for help on the str class.

help> quit

You are now leaving help and returning to the Python interpreter.
If you want to ask for help on a particular object directly from the
interpreter, you can type "help(object)".  Executing "help('string')"
has the same effect as typing a particular string at the help> prompt.
>>> 

---退出帮助模式使用quit

如果参数是字符串，则该字符串将作为模块、函数、类、方法、关键字或文档主题的名称查找，并在控制台上打印帮助页。

>>> help("time")
Help on built-in module time:

NAME
    time - This module provides various functions to manipulate time values.

DESCRIPTION
    There are two standard representations of time.  One is the number
    of seconds since the Epoch, in UTC (a.k.a. GMT).  It may be an integer
    or a floating point number (to represent fractions of seconds).
    The Epoch is system-defined; on Unix, it is generally January 1st, 1970.
    The actual value can be retrieved by calling gmtime(0).

    The other representation is a tuple of 9 integers giving local time.
    The tuple items are:
      year (including century, e.g. 1998)
      month (1-12)
      day (1-31)
      hours (0-23)
      minutes (0-59)
      seconds (0-59)
      weekday (0-6, Monday is 0)
      Julian day (day in the year, 1-366)
      DST (Daylight Savings Time) flag (-1, 0 or 1)
    If the DST flag is 0, the time is given in the regular time zone;
    if it is 1, the time is given in the DST time zone;
    if it is -1, mktime() should guess based on the date and time.

CLASSES
    builtins.tuple(builtins.object)
        struct_time

    class struct_time(builtins.tuple)
     |  struct_time(iterable=(), /)
.
.
.
.
.
.

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。

>>> a = "test"
>>> help(a)
Help on package test:

NAME
    test - # Dummy file to make this directory a package.

PACKAGE CONTENTS
    __main__
    _test_multiprocessing
    ann_module
    ann_module2
    ann_module3
    audiotests
    autotest
    bad_coding
    bad_coding2
    bad_getattr
    bad_getattr2
    bad_getattr3
    badsyntax_3131
    badsyntax_future10
    badsyntax_future3
    badsyntax_future4
    badsyntax_future5
    badsyntax_future6
    badsyntax_future7
    badsyntax_future8
    badsyntax_future9
    badsyntax_pep3120
    bisect
    bytecode_helper
.
.
.
.
.
.

>>> help("ls")
No Python documentation found for 'ls'.
Use help() to get the interactive help utility.
Use help(str) for help on the str class.

此函数由站点模块添加到内置命名空间中。

版本3.4中的更改：pydoc和inspect的更改意味着所报告的可调用签名现在更加全面和一致。

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参考：

1. Python 3.7.2 documentation

2. RUNOOB.COM：https://www.runoob.com/python/python-func-help.html

备注：

初次编辑时间：2019年9月21日21:08:21

环境：Windows 7   / Python 3.7.2