如何知道我们可以在python中对list执行的所有操作？

Question

在处理列表时，有时会出现“list object has no attribute”类型的结果怎么样我认为最好知道我们能做哪些内部操作 在名单上表演。你知道吗

Answer 1

可以对list对象运行^{}来获取属性。你知道吗

dir([])

将显示：

 ['__add__',
 '__class__',
 '__contains__',
 '__delattr__',
 '__delitem__',
 '__dir__',
 '__doc__',
 '__eq__',
 '__format__',
 '__ge__',
 '__getattribute__',
 '__getitem__',
 '__gt__',
 '__hash__',
 '__iadd__',
 '__imul__',
 '__init__',
 '__init_subclass__',
 '__iter__',
 '__le__',
 '__len__',
 '__lt__',
 '__mul__',
 '__ne__',
 '__new__',
 '__reduce__',
 '__reduce_ex__',
 '__repr__',
 '__reversed__',
 '__rmul__',
 '__setattr__',
 '__setitem__',
 '__sizeof__',
 '__str__',
 '__subclasshook__',
 'append',
 'clear',
 'copy',
 'count',
 'extend',
 'index',
 'insert',
 'pop',
 'remove',
 'reverse',
 'sort']

Answer 2

主要有两种方法。你知道吗

1. 使用^{}列出与对象相关的所有属性。你知道吗

   attempt to return a list of valid attributes for that object

   >>> dir(list)
   => ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
       '__dir__', '__doc__', '__eq__', '__format__', '__ge__',
       '__getattribute__', '__getitem__', '__gt__', '__hash__', '__iadd__',
       '__imul__', '__init__', '__init_subclass__', '__iter__', '__le__',
       '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', 
       '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', 
       '__setattr__', '__setitem__', '__sizeof__', '__str__', 
       '__subclasshook__', 'append', 'clear', 'copy', 'count', 'extend', 
       'index', 'insert', 'pop', 'remove', 'reverse', 'sort']
   

2. 使用^{}获得所有相关函数、属性等的关联列表

   Invoke the built-in help system

   >>> help([])
   
   Help on list object:
   
   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.
   
   ... and so on