python中如何使用help()

help()函数帮助我们了解模块、类型、对象、方法、属性的详细信息。

1、帮助查看类型详细信息，包含类的创建方式、属性、方法

>>> help(list)
Help on class list in module builtins:
class list(object)
 |  list() -> new empty list
 |  list(iterable) -> new list initialized from iterable's items
 |
 |  Methods defined here:
 |
 |  __add__(self, value, /)
 |      Return self+value.
 |
 |  __contains__(self, key, /)
 |      Return key in self.
 |
 |  __delitem__(self, key, /)
 |      Delete self[key].
 |
 |  __eq__(self, value, /)
 |      Return self==value.
 |
 |  __ge__(self, value, /)
 |      Return self>=value.
 |
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |
 |  __getitem__(...)
 |      x.__getitem__(y) <==> x[y]
 |
 |  __gt__(self, value, /)
 |      Return self>value.
 |
 |  __iadd__(self, value, /)
 |      Implement self+=value.
 |
 |  __imul__(self, value, /)
 |      Implement self*=value.
 |
 |  __init__(self, /, *args, **kwargs)
-- More  --

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2、帮助查看方法的详细使用信息（使用时要注意输入完整路径，使用模块帮助时，需要先导入模块）

>>> from selenium.webdriver.common.by import By
>>> help(By)
Help on class By in module selenium.webdriver.common.by:
class By(builtins.object)
 |  Set of supported locator strategies.
 |
 |  Data descriptors defined here:
 |
 |  __dict__
 |      dictionary for instance variables (if defined)
 |
 |  __weakref__
 |      list of weak references to the object (if defined)
 |
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |
 |  CLASS_NAME = 'class name'
 |
 |  CSS_SELECTOR = 'css selector'
 |
 |  ID = 'id'
 |
 |  LINK_TEXT = 'link text'
 |
 |  NAME = 'name'
 |
 |  PARTIAL_LINK_TEXT = 'partial link text'
 |
 |  TAG_NAME = 'tag name'
 |
 |  XPATH = 'xpath'
>>>

3、举例如下：

查看python所有的关键字：help("keywords")

查看python所有的modules：help("modules")

查看python所有的modules中包含指定字符串的modules： help("modules yourstr")

查看python中常见的topics： help("topics")

查看python标准库中的module：import os.path + help("os.path")

查看python内置的类型：help("list")

查看python类型的成员方法：help("str.find")

查看python内置函数：help("open")