python 怎么查看函数的用法

1、help()

help()函数可以比较详细的介绍一个函数的使用方法。

如:

>>>help(print)
Helponbuilt-infunctionprintinmodulebuiltins:
print(...)
print(value,...,sep='',end='\n',file=sys.stdout,flush=False)
Printsthevaluestoastream,ortosys.stdoutbydefault.
Optionalkeywordarguments:
file:afile-likeobject(stream);defaultstothecurrentsys.stdout.
sep:stringinsertedbetweenvalues,defaultaspace.
end:stringappendedafterthelastvalue,defaultanewline.
flush:whethertoforciblyflushthestream.

相关推荐：《Python入门教程》

2、dir()

dir()函数可以列出所查询内容的内置属性和方法。

如：

>>>dir(str)
['__add__','__class__','__contains__','__delattr__','__dir__','__doc__','__eq__','__format__','__ge__',
'__getattribute__','__getitem__','__getnewargs__','__gt__','__hash__','__init__','__init_subclass__',
'__iter__','__le__','__len__','__lt__','__mod__','__mul__','__ne__','__new__','__reduce__','__reduce_ex__',
'__repr__','__rmod__','__rmul__','__setattr__','__sizeof__','__str__','__subclasshook__','capitalize',
'casefold','center','count','encode','endswith','expandtabs','find','format','format_map','index','isalnum',
'isalpha','isascii','isdecimal','isdigit','isidentifier','islower','isnumeric','isprintable','isspace',
'istitle','isupper','join','ljust','lower','lstrip','maketrans','partition','replace','rfind','rindex',
'rjust','rpartition','rsplit','rstrip','split','splitlines','startswith','strip','swapcase','title',
'translate','upper','zfill']

dir()也可以查询python的内置方法。

>>>dir(__builtins__)
['ArithmeticError','AssertionError','AttributeError','BaseException','BlockingIOError','BrokenPipeError',
'BufferError','BytesWarning','ChildProcessError','ConnectionAbortedError','ConnectionError',
'ConnectionRefusedError','ConnectionResetError','DeprecationWarning','EOFError','Ellipsis','EnvironmentError',
'Exception','False','FileExistsError','FileNotFoundError','FloatingPointError','FutureWarning','GeneratorExit',
'IOError','ImportError','ImportWarning','IndentationError','IndexError','InterruptedError','IsADirectoryError',
'KeyError','KeyboardInterrupt','LookupError','MemoryError','ModuleNotFoundError','NameError','None',
'NotADirectoryError','NotImplemented','NotImplementedError','OSError','OverflowError','PendingDeprecationWarning',
'PermissionError','ProcessLookupError','RecursionError','ReferenceError','ResourceWarning','RuntimeError',
'RuntimeWarning','StopAsyncIteration','StopIteration','SyntaxError','SyntaxWarning','SystemError','SystemExit',
'TabError','TimeoutError','True','TypeError','UnboundLocalError','UnicodeDecodeError','UnicodeEncodeError',
'UnicodeError','UnicodeTranslateError','UnicodeWarning','UserWarning','ValueError','Warning','WindowsError',
'ZeroDivisionError','_','__build_class__','__debug__','__doc__','__import__','__loader__','__name__',
'__package__','__spec__','abs','all','any','ascii','bin','bool','breakpoint','bytearray','bytes',
'callable','chr','classmethod','compile','complex','copyright','credits','delattr','dict','dir','divmod',
'enumerate','eval','exec','exit','filter','float','format','frozenset','getattr','globals','hasattr',
'hash','help','hex','id','input','int','isinstance','issubclass','iter','len','license','list','locals',
'map','max','memoryview','min','next','object','oct','open','ord','pow','print','property','quit',
'range','repr','reversed','round','set','setattr','slice','sorted','staticmethod','str','sum','super',
'tuple','type','vars','zip']

3、xx.__doc__

查看使用帮助，一般为创建该类时候的备注。

4、xx.__dict__

查看对象所拥有的属性。

5、在IDLE中点击help中的python docs

在输入栏中打上你要查找的内容直接搜索，不过这里应该只有python自带的一下基本的模块。