是否可以使用命令行獲得給定函數的詳細幫助？

Question

我是一個新的Python用戶:) 是否可以使用命令行獲得給定函數的詳細幫助？

Answer 1

由於蟒蛇告訴你，當你啓動CLI：

 
Type "help", "copyright", "credits" or "license" for more information. 
>>> 

只要求help：

help(help) 
help(list) 
help(locals) 
import math 
help(math) 
help(math.atan2) 

Answer 2

如果你的意思是使用shell命令行，這裏是一個可能的解決方案：

python -c "help(help)" 

Answer 3

對於大多數模塊：

Python 2.6.7 (r267:88850, Sep 23 2011, 00:28:08) 
.... 
Type "help", "copyright", "credits" or "license" for more information. 
>>> import os 
>>> help(os) 

>>> print os.__doc__ 
OS routines for Mac, NT, or Posix depending on what system we're on. 

This exports: 
    - all functions from posix, nt, os2, or ce, e.g. unlink, stat, etc. 
    - os.path is one of the modules posixpath, or ntpath 
    - os.name is 'posix', 'nt', 'os2', 'ce' or 'riscos' 
    - os.curdir is a string representing the current directory ('.' or ':') 
    - os.pardir is a string representing the parent directory ('..' or '::') 
    - os.sep is the (or a most common) pathname separator ('/' or ':' or '\\') 
    ..... 
>>> 

Answer 4

如果你的意思，然後Python的命令提示符：

help(whatever) 

，或者如果whatever是保留字：

help("whatever") 

如果你指的殼或Windows命令提示符，然後使用是pydoc ：

C:\Python32>lib\pydoc.py json.dumps 
Help on function dumps in json: 

json.dumps = dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, s 
eparators=None, default=None, **kw) 
    Serialize ``obj`` to a JSON formatted ``str``. 

    If ``skipkeys`` is false then ``dict`` keys that are not basic types 
    (``str``, ``int``, ``float``, ``bool``, ``None``) will be skipped 
    instead of raising a ``TypeError``. 

    If ``ensure_ascii`` is false, then the return value can contain non-ASCII 
    characters if they appear in strings contained in ``obj``. Otherwise, all 
    such characters are escaped in JSON strings. 

    If ``check_circular`` is false, then the circular reference check 
    for container types will be skipped and a circular reference will 
    result in an ``OverflowError`` (or worse). 

    If ``allow_nan`` is false, then it will be a ``ValueError`` to 
    serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``) in 
    strict compliance of the JSON specification, instead of using the 
    JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``). 

    If ``indent`` is a non-negative integer, then JSON array elements and 
    object members will be pretty-printed with that indent level. An indent 
    level of 0 will only insert newlines. ``None`` is the most compact 
    representation. 

    If ``separators`` is an ``(item_separator, dict_separator)`` tuple 
    then it will be used instead of the default ``(', ', ': ')`` separators. 
    ``(',', ':')`` is the most compact JSON representation. 

    ``default(obj)`` is a function that should return a serializable version 
    of obj or raise TypeError. The default simply raises TypeError. 

    To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the 
    ``.default()`` method to serialize additional types), specify it with 
    the ``cls`` kwarg; otherwise ``JSONEncoder`` is used. 

Answer 5

您可以使用pydoc

Answer 6

考慮安裝IPython。它不僅讓您快速方便地訪問help doc strings：

In [3]: os.path.expanduser? 
Type:  function 
Base Class: <type 'function'> 
String Form: <function expanduser at 0xb77ffe64> 
Namespace: Interactive 
File:  /usr/lib/python2.7/posixpath.py 
Definition: os.path.expanduser(path) 
Docstring: 
    Expand ~ and ~user constructions. If user or $HOME is unknown, 
    do nothing. 

它也可以幫助你找出什麼屬性/方法的對象必須通過tab completion：

os.path.__name__     os.path.ismount 
os.path.__new__      os.path.join 
os.path.__package__     os.path.lexists 
os.path.__reduce__     os.path.normcase 
os.path.__reduce_ex__    os.path.normpath 
os.path.__repr__     os.path.os 
os.path.__setattr__     os.path.pardir 
os.path.__sizeof__     os.path.pathsep 
os.path.__str__      os.path.realpath 
os.path.__subclasshook__   os.path.relpath 
os.path._resolve_link    os.path.samefile 
os.path._varprog     os.path.sameopenfile 
os.path.abspath      os.path.samestat 
os.path.altsep      os.path.sep 
os.path.basename     os.path.split 
os.path.commonprefix    os.path.splitdrive 
os.path.curdir      os.path.splitext 
os.path.defpath      os.path.stat 
os.path.devnull      os.path.supports_unicode_filenames 
os.path.dirname      os.path.sys 
os.path.exists      os.path.walk 
os.path.expanduser     os.path.warnings 

In [4]: os.path.[TAB] 

在Debian/Ubuntu的，IPython中能被安裝與

sudo apt-get install ipython