Python学习笔记(一):list属性及方法浅析

      In [1]: a = list()
      In [2]: a
      Out[2]: []
  
 

      In [6]: s = "hello world!"
      In [7]: L = list(s)
      In [8]: L
      Out[8]: ['h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', '!']
  
 

      In [1]: a = [1,2]
      In [2]: b = [1,2]
      In [3]: a.__add__(b)   # 返回a+b，a,b本身没有改变
      Out[3]: [1, 2, 1, 2]
      In [4]: a
      Out[4]: [1, 2]
      In [5]: b
      Out[5]: [1, 2]
      In [6]: c = a.__add__(b)
      In [7]: c
      Out[7]: [1, 2, 1, 2]
      In [8]: d = a+b
      In [9]: c == b
      Out[9]: False
      In [10]: c == d
      Out[10]: True
  
 

      In [11]: L = [1,2,3,4]
      In [12]: L.__contains__(1)
      Out[12]: True
      In [13]: L.__contains__(2)
      Out[13]: True
      In [14]: L.__contains__(0)
      Out[14]: False
      In [15]: L.__contains__('a')
      Out[15]: False
      In [16]: L.__contains__(L)   #并不包含本身
      Out[16]: False
      In [18]: L in L
      Out[18]: False
      In [19]: 2 in L
      Out[19]: True
      In [20]: 0 in L
      Out[20]: False
  
 

      In [21]: L = [1,2,3]
      In [22]: L.__delitem__(0)   #删除第0个对象
      In [23]: L
      Out[23]: [2, 3]
      In [24]: del L[1] #删除第1个对象
      In [25]: L
      Out[25]: [2]
  
 

      In [36]: a = [1,2,3,4]
      In [37]: b = [1,2]
      In [38]: a.__eq__(1)
      Out[38]: NotImplemented   #没有实现该功能
      In [39]: a.__eq__([1,2])
      Out[39]: False
      In [40]: a.__eq__(b)
      Out[40]: False
      In [41]: a.__eq__([1,2,3,4])
      Out[41]: True
      In [42]: a.__eq__((1,2,3,4))
      Out[42]: NotImplemented
      与 == 略有差异
      In [43]: a = [1,2,3,4]
      In [44]: b = [1,2]
      In [45]: a == 1
      Out[45]: False
      In [46]: a == [1,2]
      Out[46]: False
      In [47]: a == [1,2,3,4]
      Out[47]: True
      In [48]: a == b
      Out[48]: False
      In [49]: a == (1,2,3,4)
      Out[49]: False
  
 

      In [63]: a = [1,2,3,4]
      In [64]: a.__getattribute__('__len__')
      Out[64]: <method-wrapper '__len__' of list object at 0x02558EE0>
      In [65]: b = a.__getattribute__('__len__')
      In [66]: b()
      Out[66]: 4
      In [67]: a
      Out[67]: [1, 2, 3, 4]
      In [68]: a.__getattribute__('copy')
      Out[68]: <function list.copy>
      In [69]: b = a.__getattribute__('copy')
      In [70]: c = b()
      In [71]: c
      Out[71]: [1, 2, 3, 4]
  
 

      In [1]: a = [1,2,3,"hello",(1,2,3)]
      In [2]: a.__getitem__(0)
      Out[2]: 1
      In [3]: a.__getitem__(3)
      Out[3]: 'hello'
      In [4]: a.__getitem__(4)
      Out[4]: (1, 2, 3)
      In [5]: a.__getitem__(5) 无法访问越界的对象
      ---------------------------------------------------------------------------
      IndexError Traceback (most recent call last)
      <ipython-input-5-3a58e3eacf6a> in <module>()
      ----> 1 a.__getitem__(5)
      IndexError: list index out of range #越界报错
      In [6]:  a = [1,2,3,"hello",(1,2,3)]
      In [7]: a[0]
      Out[7]: 1
      In [8]: a[3]
      Out[8]: 'hello'
      In [9]: a[4]
      Out[9]: (1, 2, 3)
      In [10]: a[5]
      ---------------------------------------------------------------------------
      IndexError Traceback (most recent call last)
      <ipython-input-10-b6a934feab86> in <module>()
      ----> 1 a[5]
      IndexError: list index out of range
  
 

      In [3]: a = [1,2,3,4]
      In [4]: a.__iadd__("hello")
      Out[4]: [1, 2, 3, 4, 'h', 'e', 'l', 'l', 'o'] #先将字符串转换为列表，然后再相加，列表会改变
      In [5]: a.__iadd__((1,2,3))
      Out[5]: [1, 2, 3, 4, 'h', 'e', 'l', 'l', 'o', 1, 2, 3]  #先将元组转换为列表，然后再相加，列表会改变
      In [6]: a.__iadd__([1111,1113])   #列表相加，列表会改变
      Out[6]: [1, 2, 3, 4, 'h', 'e', 'l', 'l', 'o', 1, 2, 3, 1111, 1113]
      In [7]: a #a已改变
      Out[7]: [1, 2, 3, 4, 'h', 'e', 'l', 'l', 'o', 1, 2, 3, 1111, 1113]
  
 

      In [15]: a = [1,2,3,'abc']
      In [16]: a.__imul__(2) #*2并返回给a
      Out[16]: [1, 2, 3, 'abc', 1, 2, 3, 'abc']
      In [17]: a #a已改变
      Out[17]: [1, 2, 3, 'abc', 1, 2, 3, 'abc']
      In [18]: a.__imul__([1,2])  #参数不是integer类型，报错
      ---------------------------------------------------------------------------
      TypeError Traceback (most recent call last)
      <ipython-input-18-58ca78754a99> in <module>()
      ----> 1 a.__imul__([1,2])
      TypeError: 'list' object cannot be interpreted as an integer
  
 

      In [23]: a = []
      In [24]: b = [1,2,3,4]
      In [25]: a.__init__(b)
      In [26]: a
      Out[26]: [1, 2, 3, 4]
      In [27]: a.__init__((1,2,3))  #先将元组转换为列表，再初始化给a
      In [28]: a
      Out[28]: [1, 2, 3]
  
 

      In [34]: a = [1,2,3,4,54]
      In [35]: for i  in a.__iter__():
       ...: print (i)
       ...:
      1
      2
      3
      4
      54
      In [36]: a.__iter__
      Out[36]: <method-wrapper '__iter__' of list object at 0x024B7D00>
      In [37]: a.__iter__()   #列表类型的迭代器
      Out[37]: <list_iterator at 0x25586b0>
  
 

__le__(self, value, /)      Return self<=value.  判断列表是不大于某列表。与__eq__类似

      In [38]: a = [1,2,3,"abc",(111,222,333)]
      In [39]: a.__len__()
      Out[39]: 5
      In [40]: a.__len__
      Out[40]: <method-wrapper '__len__' of list object at 0x024C44B8>
  
 

      In [41]: a = [1,2,3,"abc",(111,222,333)]
      In [42]: a.__mul__(2)
      Out[42]: [1, 2, 3, 'abc', (111, 222, 333), 1, 2, 3, 'abc', (111, 222, 333)]
      In [43]: a
      Out[43]: [1, 2, 3, 'abc', (111, 222, 333)]
  
 

      In [1]: a = [1,2,3,4]
      In [2]: b = a.__new__(list)
      In [3]: b
      Out[3]: []
      In [4]: b = a.__new__(str)
      ---------------------------------------------------------------------------
      TypeError Traceback (most recent call last)
      <ipython-input-4-6fee1f0c3d80> in <module>()
      ----> 1 b = a.__new__(str)
      TypeError: list.__new__(str): str is not a subtype of list
      In [5]: b = a.__new__(tuple)
      ---------------------------------------------------------------------------
      TypeError Traceback (most recent call last)
      <ipython-input-5-18991a398a58> in <module>()
      ----> 1 b = a.__new__(tuple)
      TypeError: list.__new__(tuple): tuple is not a subtype of list
  
 

      In [12]: a = [1,2,3,4]
      In [13]: b = a.__repr__()
      In [14]: b
      Out[14]: '[1, 2, 3, 4]'   #字符串
      In [15]: a
      Out[15]: [1, 2, 3, 4]
  
 

      In [19]: a = [1,2,3,4]
      In [20]: a.__reversed__()
      Out[20]: <list_reverseiterator at 0x2538c50>
      In [21]: a
      Out[21]: [1, 2, 3, 4]
      In [22]: b = a.__reversed__()
      In [23]: for i in b:
       ...: print (i)
       ...:
      4
      3
      2
      1
  
 

      In [34]: a = [1,2,3,4,"abc"]
      In [35]: a.__mul__(-1)
      Out[35]: []
      In [36]: a.__mul__(0)
      Out[36]: []
      In [37]: a
      Out[37]: [1, 2, 3, 4, 'abc']
      In [38]: a.__mul__(2)
      Out[38]: [1, 2, 3, 4, 'abc', 1, 2, 3, 4, 'abc']
  
 

      In [39]: a
      Out[39]: [1, 2, 3, 4, 'abc']
      In [40]: a.__setitem__(2,"aaa")
      In [41]: a
      Out[41]: [1, 2, 'aaa', 4, 'abc']
      In [43]: a
      Out[43]: [1, 2, 3, 4, 'abc']
  
 

      In [44]: a = []
      In [45]: a.__sizeof__
      Out[45]: <function list.__sizeof__>
      In [46]: a.__sizeof__()
      Out[46]: 20
      In [47]: a = [1]
      In [48]: a.__sizeof__()
      Out[48]: 24
      In [49]: a = [1,2,3]
      In [50]: a.__sizeof__()
      Out[50]: 32
      In [51]: a = ['a']
      In [52]: a.__sizeof__()
      Out[52]: 24
      In [53]: a = ['abc']
      In [54]: a.__sizeof__()
      Out[54]: 24
  
 

      In [55]: a = [1]
      In [56]: a.append(2)
      In [57]: a
      Out[57]: [1, 2]
      In [58]: a.append('2')
      In [59]: a
      Out[59]: [1, 2, '2']
      In [60]: a.append([1,2])
      In [61]: a
      Out[61]: [1, 2, '2', [1, 2]]
      In [62]: a.append((3,4))
      In [63]: a
      Out[63]: [1, 2, '2', [1, 2], (3, 4)]
  
 

      In [64]: a
      Out[64]: [1, 2, '2', [1, 2], (3, 4)]
      In [65]: a.clear()
      In [66]: a
      Out[66]: []
  
 

      In [67]: a = [1,2,3,4]
      In [68]: b = a.copy()
      In [69]: a
      Out[69]: [1, 2, 3, 4]
      In [70]: b
      Out[70]: [1, 2, 3, 4]
  
 

      In [71]: a = [1,2,3,'a','aa',[1,2]]
      In [72]: a.count(1)
      Out[72]: 1
      In [73]: a.count('a')
      Out[73]: 1
      In [74]: a.count([1,2])
      Out[74]: 1
      In [75]: a.count(0)
      Out[75]: 0
  
 

      In [80]: a = [1,2,3]
      In [81]: a.extend((1,2,3))
      In [82]: a
      Out[82]: [1, 2, 3, 1, 2, 3]
      In [83]: a.extend([4,5,6])
      In [84]: a
      Out[84]: [1, 2, 3, 1, 2, 3, 4, 5, 6]
  
 

      In [85]: a
      Out[85]: [1, 2, 3, 1, 2, 3, 4, 5, 6]
      In [86]: a.index(2)
      Out[86]: 1 #返回第一个出现对象的位置
      In [87]: a.index(7)  #列表中不存在是时报错
      ---------------------------------------------------------------------------
      ValueError Traceback (most recent call last)
      <ipython-input-87-e64802c95647> in <module>()
      ----> 1 a.index(7)
      ValueError: 7 is not in list
  
 

      In [90]: a.insert(0,"abc")
      In [91]: a
      Out[91]: ['abc', 1, 2, 3, 1, 2, 3, 4, 5, 6]
  
 

      In [92]: a.pop(2)
      Out[92]: 2
      In [93]: a
      Out[93]: ['abc', 1, 3, 1, 2, 3, 4, 5, 6]
  
 

      In [100]: a = [1,1,2,2,3,3,4,4,"aa",'aa']
      In [101]: a.remove(1)
      In [102]: a
      Out[102]: [1, 2, 2, 3, 3, 4, 4, 'aa', 'aa']
      In [103]: a.remove('aa')
      In [104]: a
      Out[104]: [1, 2, 2, 3, 3, 4, 4, 'aa']
  
 

      In [105]: a = [1,2,3]
      In [106]: a.reverse()
      In [107]: a
      Out[107]: [3, 2, 1]
  
 

      In [112]: a = [1,9,2,3,7,4]
      In [113]: a.sort()
      In [114]: a
      Out[114]: [1, 2, 3, 4, 7, 9]
  
 

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原文链接：blog.csdn.net/qq523176585/article/details/77978925