Python help 函数

基础 Python 学习路线推荐 : Python 学习目录 >> Python 基础入门


       Python 3.x 版本虽然比 2.x 少了一些内置函数,但是 Python 内置 函数没有60个,也有 40 个,那么多内置函数你记得过来吗?为了方便使用,Python 提供了help 函数专门用来提供查看函数或模块用途的详细说明;


一.Python help 函数简介

'''
参数:
    object – 对象/函数名/模块;

返回值 – 返回对象的帮助信息;
'''
help([object])

二.Python help 函数使用


1.查看内置函数的帮助信息

# !usr/bin/env python
# !usr/bin/env python
# -*- coding:utf-8 _*-
"""
@Author:猿说编程
@Blog(个人博客地址): www.codersrc.com
@File:Python help 函数.py
@Time:2021/05/11 07:37
@Motto:不积跬步无以至千里,不积小流无以成江海,程序人生的精彩需要坚持不懈地积累!
 
"""

print(help(type)) # 内置函数type  - 获取数据变量类型

'''
输出结果:

Help on class type in module builtins:

class type(object)
 |  type(object_or_name, bases, dict)
 |  type(object) -> the object's type
 |  type(name, bases, dict) -> a new type
 |  
 |  Methods defined here:
 |  
 |  __call__(self, /, *args, **kwargs)
 |      Call self as a function.
 |  
 |  __delattr__(self, name, /)
 |      Implement delattr(self, name).
 |  
 |  __dir__(...)
 |      __dir__() -> list
 |      specialized __dir__ implementation for types
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __init__(self, /, *args, **kwargs)
 |      Initialize self.  See help(type(self)) for accurate signature.
 |  
 |  __instancecheck__(...)
 |      __instancecheck__() -> bool
 |      check if an object is an instance
 |  
 |  __new__(*args, **kwargs)
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  __prepare__(...)
 |      __prepare__() -> dict
 |      used to create the namespace for the class statement
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __setattr__(self, name, value, /)
 |      Implement setattr(self, name, value).
 |  
 |  __sizeof__(...)
 |      __sizeof__() -> int
 |      return memory consumption of the type object
 |  
 |  __subclasscheck__(...)
 |      __subclasscheck__() -> bool
 |      check if a class is a subclass
 |  
 |  __subclasses__(...)
 |      __subclasses__() -> list of immediate subclasses
 |  
 |  mro(...)
 |      mro() -> list
 |      return a type's method resolution order
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |  
 |  __abstractmethods__
 |  
 |  __dict__
 |  
 |  __text_signature__
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  __base__ = <class 'object'>
 |      The most base type
 |  
 |  __bases__ = (<class 'object'>,)
 |  
 |  __basicsize__ = 864
 |  
 |  __dictoffset__ = 264
 |  
 |  __flags__ = -2146675712
 |  
 |  __itemsize__ = 40
 |  
 |  __mro__ = (<class 'type'>, <class 'object'>)
 |  
 |  __weakrefoffset__ = 368

None

Process finished with exit code 0
'''

2.查看数据类型的帮助信息

# !usr/bin/env python
# !usr/bin/env python
# -*- coding:utf-8 _*-
"""
@Author:猿说编程
@Blog(个人博客地址): www.codersrc.com
@File:Python help 函数.py
@Time:2021/05/11 07:37
@Motto:不积跬步无以至千里,不积小流无以成江海,程序人生的精彩需要坚持不懈地积累!
 
"""


print(help(str))  # 内置数据变量类型 - 字符

'''
输出结果:


Help on class str in module builtins:

class str(object)
 |  str(object='') -> str
 |  str(bytes_or_buffer[, encoding[, errors]]) -> str
 |  
 |  Create a new string object from the given object. If encoding or
 |  errors is specified, then the object must expose a data buffer
 |  that will be decoded using the given encoding and error handler.
 |  Otherwise, returns the result of object.__str__() (if defined)
 |  or repr(object).
 |  encoding defaults to sys.getdefaultencoding().
 |  errors defaults to 'strict'.
 |  
 |  Methods defined here:
 |  
 |  __add__(self, value, /)
 |      Return self+value.
 |  
 |  __contains__(self, key, /)
 |      Return key in self.
 |  
 |  __eq__(self, value, /)
 |      Return self==value.
 |  
 |  __format__(...)
 |      S.__format__(format_spec) -> str
 |      
 |      Return a formatted version of S as described by format_spec.
 |  
 |  __ge__(self, value, /)
 |      Return self>=value.
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __getitem__(self, key, /)
 |      Return self[key].
 |  
 |  __getnewargs__(...)
 |  
 |  __gt__(self, value, /)
 |      Return self>value.
 |  
 |  __hash__(self, /)
 |      Return hash(self).
 |  
 |  __iter__(self, /)
 |      Implement iter(self).
 |  
 |  __le__(self, value, /)
 |      Return self<=value.
 |  
 |  __len__(self, /)
 |      Return len(self).
 |  
 |  __lt__(self, value, /)
 |      Return self<value.
 |  
 |  __mod__(self, value, /)
 |      Return self%value.
 |  
 |  __mul__(self, value, /)
 |      Return self*value.n
 |  
 |  __ne__(self, value, /)
 |      Return self!=value.
 |  
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __rmod__(self, value, /)
 |      Return value%self.
 |  
 |  __rmul__(self, value, /)
 |      Return self*value.
 |  
 |  __sizeof__(...)
 |      S.__sizeof__() -> size of S in memory, in bytes
 |  
 |  __str__(self, /)
 |      Return str(self).
 |  
 |  capitalize(...)
 |      S.capitalize() -> str
 |      
 |      Return a capitalized version of S, i.e. make the first character
 |      have upper case and the rest lower case.
 |  
 |  casefold(...)
 |      S.casefold() -> str
 |      
 |      Return a version of S suitable for caseless comparisons.
 |  
 |  center(...)
 |      S.center(width[, fillchar]) -> str
 |      
 |      Return S centered in a string of length width. Padding is
 |      done using the specified fill character (default is a space)
 |  
 |  count(...)
 |      S.count(sub[, start[, end]]) -> int
 |      
 |      Return the number of non-overlapping occurrences of substring sub in
 |      string S[start:end].  Optional arguments start and end are
 |      interpreted as in slice notation.
 |  
 |  encode(...)
 |      S.encode(encoding='utf-8', errors='strict') -> bytes
 |      
 |      Encode S using the codec registered for encoding. Default encoding
 |      is 'utf-8'. errors may be given to set a different error
 |      handling scheme. Default is 'strict' meaning that encoding errors raise
 |      a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
 |      'xmlcharrefreplace' as well as any other name registered with
 |      codecs.register_error that can handle UnicodeEncodeErrors.
 |  
 |  endswith(...)
 |      S.endswith(suffix[, start[, end]]) -> bool
 |      
 |      Return True if S ends with the specified suffix, False otherwise.
 |      With optional start, test S beginning at that position.
 |      With optional end, stop comparing S at that position.
 |      suffix can also be a tuple of strings to try.
 |  
 |  expandtabs(...)
 |      S.expandtabs(tabsize=8) -> str
 |      
 |      Return a copy of S where all tab characters are expanded using spaces.
 |      If tabsize is not given, a tab size of 8 characters is assumed.
 |  
 |  find(...)
 |      S.find(sub[, start[, end]]) -> int
 |      
 |      Return the lowest index in S where substring sub is found,
 |      such that sub is contained within S[start:end].  Optional
 |      arguments start and end are interpreted as in slice notation.
 |      
 |      Return -1 on failure.
 |  
 |  format(...)
 |      S.format(*args, **kwargs) -> str
 |      
 |      Return a formatted version of S, using substitutions from args and kwargs.
 |      The substitutions are identified by braces ('{' and '}').
 |  
 |  format_map(...)
 |      S.format_map(mapping) -> str
 |      
 |      Return a formatted version of S, using substitutions from mapping.
 |      The substitutions are identified by braces ('{' and '}').
 |  
 |  index(...)
 |      S.index(sub[, start[, end]]) -> int
 |      
 |      Return the lowest index in S where substring sub is found, 
 |      such that sub is contained within S[start:end].  Optional
 |      arguments start and end are interpreted as in slice notation.
 |      
 |      Raises ValueError when the substring is not found.
 |  
 |  isalnum(...)
 |      S.isalnum() -> bool
 |      
 |      Return True if all characters in S are alphanumeric
 |      and there is at least one character in S, False otherwise.
 |  
 |  isalpha(...)
 |      S.isalpha() -> bool
 |      
 |      Return True if all characters in S are alphabetic
 |      and there is at least one character in S, False otherwise.
 |  
 |  isdecimal(...)
 |      S.isdecimal() -> bool
 |      
 |      Return True if there are only decimal characters in S,
 |      False otherwise.
 |  
 |  isdigit(...)
 |      S.isdigit() -> bool
 |      
 |      Return True if all characters in S are digits
 |      and there is at least one character in S, False otherwise.
 |  
 |  isidentifier(...)
 |      S.isidentifier() -> bool
 |      
 |      Return True if S is a valid identifier according
 |      to the language definition.
 |      
 |      Use keyword.iskeyword() to test for reserved identifiers
 |      such as "def" and "class".
 |  
 |  islower(...)
 |      S.islower() -> bool
 |      
 |      Return True if all cased characters in S are lowercase and there is
 |      at least one cased character in S, False otherwise.
 |  
 |  isnumeric(...)
 |      S.isnumeric() -> bool
 |      
 |      Return True if there are only numeric characters in S,
 |      False otherwise.
 |  
 |  isprintable(...)
 |      S.isprintable() -> bool
 |      
 |      Return True if all characters in S are considered
 |      printable in repr() or S is empty, False otherwise.
 |  
 |  isspace(...)
 |      S.isspace() -> bool
 |      
 |      Return True if all characters in S are whitespace
 |      and there is at least one character in S, False otherwise.
 |  
 |  istitle(...)
 |      S.istitle() -> bool
 |      
 |      Return True if S is a titlecased string and there is at least one
 |      character in S, i.e. upper- and titlecase characters may only
 |      follow uncased characters and lowercase characters only cased ones.
 |      Return False otherwise.
 |  
 |  isupper(...)
 |      S.isupper() -> bool
 |      
 |      Return True if all cased characters in S are uppercase and there is
 |      at least one cased character in S, False otherwise.
 |  
 |  join(...)
 |      S.join(iterable) -> str
 |      
 |      Return a string which is the concatenation of the strings in the
 |      iterable.  The separator between elements is S.
 |  
 |  ljust(...)
 |      S.ljust(width[, fillchar]) -> str
 |      
 |      Return S left-justified in a Unicode string of length width. Padding is
 |      done using the specified fill character (default is a space).
 |  
 |  lower(...)
 |      S.lower() -> str
 |      
 |      Return a copy of the string S converted to lowercase.
 |  
 |  lstrip(...)
 |      S.lstrip([chars]) -> str
 |      
 |      Return a copy of the string S with leading whitespace removed.
 |      If chars is given and not None, remove characters in chars instead.
 |  
 |  partition(...)
 |      S.partition(sep) -> (head, sep, tail)
 |      
 |      Search for the separator sep in S, and return the part before it,
 |      the separator itself, and the part after it.  If the separator is not
 |      found, return S and two empty strings.
 |  
 |  replace(...)
 |      S.replace(old, new[, count]) -> str
 |      
 |      Return a copy of S with all occurrences of substring
 |      old replaced by new.  If the optional argument count is
 |      given, only the first count occurrences are replaced.
 |  
 |  rfind(...)
 |      S.rfind(sub[, start[, end]]) -> int
 |      
 |      Return the highest index in S where substring sub is found,
 |      such that sub is contained within S[start:end].  Optional
 |      arguments start and end are interpreted as in slice notation.
 |      
 |      Return -1 on failure.
 |  
 |  rindex(...)
 |      S.rindex(sub[, start[, end]]) -> int
 |      
 |      Return the highest index in S where substring sub is found,
 |      such that sub is contained within S[start:end].  Optional
 |      arguments start and end are interpreted as in slice notation.
 |      
 |      Raises ValueError when the substring is not found.
 |  
 |  rjust(...)
 |      S.rjust(width[, fillchar]) -> str
 |      
 |      Return S right-justified in a string of length width. Padding is
 |      done using the specified fill character (default is a space).
 |  
 |  rpartition(...)
 |      S.rpartition(sep) -> (head, sep, tail)
 |      
 |      Search for the separator sep in S, starting at the end of S, and return
 |      the part before it, the separator itself, and the part after it.  If the
 |      separator is not found, return two empty strings and S.
 |  
 |  rsplit(...)
 |      S.rsplit(sep=None, maxsplit=-1) -> list of strings
 |      
 |      Return a list of the words in S, using sep as the
 |      delimiter string, starting at the end of the string and
 |      working to the front.  If maxsplit is given, at most maxsplit
 |      splits are done. If sep is not specified, any whitespace string
 |      is a separator.
 |  
 |  rstrip(...)
 |      S.rstrip([chars]) -> str
 |      
 |      Return a copy of the string S with trailing whitespace removed.
 |      If chars is given and not None, remove characters in chars instead.
 |  
 |  split(...)
 |      S.split(sep=None, maxsplit=-1) -> list of strings
 |      
 |      Return a list of the words in S, using sep as the
 |      delimiter string.  If maxsplit is given, at most maxsplit
 |      splits are done. If sep is not specified or is None, any
 |      whitespace string is a separator and empty strings are
 |      removed from the result.
 |  
 |  splitlines(...)
 |      S.splitlines([keepends]) -> list of strings
 |      
 |      Return a list of the lines in S, breaking at line boundaries.
 |      Line breaks are not included in the resulting list unless keepends
 |      is given and true.
 |  
 |  startswith(...)
 |      S.startswith(prefix[, start[, end]]) -> bool
 |      
 |      Return True if S starts with the specified prefix, False otherwise.
 |      With optional start, test S beginning at that position.
 |      With optional end, stop comparing S at that position.
 |      prefix can also be a tuple of strings to try.
 |  
 |  strip(...)
 |      S.strip([chars]) -> str
 |      
 |      Return a copy of the string S with leading and trailing
 |      whitespace removed.
 |      If chars is given and not None, remove characters in chars instead.
 |  
 |  swapcase(...)
 |      S.swapcase() -> str
 |      
 |      Return a copy of S with uppercase characters converted to lowercase
 |      and vice versa.
 |  
 |  title(...)
 |      S.title() -> str
 |      
 |      Return a titlecased version of S, i.e. words start with title case
 |      characters, all remaining cased characters have lower case.
 |  
 |  translate(...)
 |      S.translate(table) -> str
 |      
 |      Return a copy of the string S in which each character has been mapped
 |      through the given translation table. The table must implement
 |      lookup/indexing via __getitem__, for instance a dictionary or list,
 |      mapping Unicode ordinals to Unicode ordinals, strings, or None. If
 |      this operation raises LookupError, the character is left untouched.
 |      Characters mapped to None are deleted.
 |  
 |  upper(...)
 |      S.upper() -> str
 |      
 |      Return a copy of S converted to uppercase.
 |  
 |  zfill(...)
 |      S.zfill(width) -> str
 |      
 |      Pad a numeric string S with zeros on the left, to fill a field
 |      of the specified width. The string S is never truncated.
 |  
 |  ----------------------------------------------------------------------
 |  Static methods defined here:
 |  
 |  maketrans(x, y=None, z=None, /)
 |      Return a translation table usable for str.translate().
 |      
 |      If there is only one argument, it must be a dictionary mapping Unicode
 |      ordinals (integers) or characters to Unicode ordinals, strings or None.
 |      Character keys will be then converted to ordinals.
 |      If there are two arguments, they must be strings of equal length, and
 |      in the resulting dictionary, each character in x will be mapped to the
 |      character at the same position in y. If there is a third argument, it
 |      must be a string, whose characters will be mapped to None in the result.

None
-10

Process finished with exit code 0
'''

三.猜你喜欢

  1. Python 条件推导式
  2. Python 列表推导式
  3. Python 字典推导式
  4. Python 不定长参数 *argc/**kargcs
  5. Python 匿名函数 lambda
  6. Python return 逻辑判断表达式
  7. Python is 和 == 区别
  8. Python 可变数据类型和不可变数据类型
  9. Python 浅拷贝和深拷贝
  10. Python 异常处理
  11. Python 线程创建和传参
  12. Python 线程互斥锁 Lock
  13. Python 线程时间 Event
  14. Python 线程条件变量 Condition
  15. Python 线程定时器 Timer
  16. Python 线程信号量 Semaphore
  17. Python 线程障碍对象 Barrier
  18. Python 线程队列 Queue – FIFO
  19. Python 线程队列 LifoQueue – LIFO
  20. Python 线程优先队列 PriorityQueue
  21. Python 线程池 ThreadPoolExecutor(一)
  22. Python 线程池 ThreadPoolExecutor(二)
  23. Python 进程 Process 模块
  24. Python 进程 Process 与线程 threading 区别
  25. Python 进程间通信 Queue / Pipe
  26. Python 进程池 multiprocessing.Pool
  27. Python GIL 锁

未经允许不得转载:猿说编程 » Python help 函数
喜欢(3) 打赏

评论抢沙发

不积跬步无以至千里,不积小流无以成江海,程序人生的精彩需要坚持不懈地积累!!

开始学习

觉得文章有用就打赏一下文章作者

支付宝扫一扫打赏

微信扫一扫打赏