python3-列表与字符串

• 2020 年 1 月 6 日
• 筆記

del如下。pop弹出元素并返回。

print(x)  [1, 2, 5, 6, 8, 4, 3, 5]    del x[3]  print(x)  [1, 2, 5, 8, 4, 3, 5]    y=x.pop()  print(y)  5    x  print(x)  [1, 2, 5, 8, 4, 3]

print(x)  [1, 2, 5, 8, 4, 3]    x  z=x.pop(3)  print(x)  [1, 2, 5, 4, 3]    z  print(z)  8

x1=(1,2,"aaaa")  x2=(3,4,"bbbb")    x1,x2  print(x1,x2)  (1, 2, 'aaaa') (3, 4, 'bbbb')  x1  (1, 2, 'aaaa')    x2  x2  (3, 4, 'bbbb')    print(x1[0],x1[1])  1 2    print(x2[2],x1[1])  bbbb 2    ```python  str='1234n5aaaaa'  print(str)  str="123n45'aaaa'a"  print(str)

1234  5aaaaa  123  45'aaaa'a

str="""  adfdf  {asdf}  //2qerffasda  """  print(str)  str='''adfdf  {asdf}  //2qerffasda'''  print(str)

adfdf  {asdf}  //2qerffasda    adfdf  {asdf}  //2qerffasda

str="""123n45'aaaa'a"""  print(str)  str='''123n45'aaaa'a'''  print(str)  str='''  123n45'aaaa'a  '''  print(str)

123  45'aaaa'a  123  45'aaaa'a    123  45'aaaa'a

str='''  123n  45'aaaa'a  '''  print(str)

123    45'aaaa'a

可见三引号中转义字符还是有作用，但使用r则可以消除转义字符的作用

str='''  123n  45'aaaa'a  aa\  bb  '''  print(str)  str=r'''  123n  45'aaaa'a  aa\  bb  '''  print(str)

123    45'aaaa'a  aa  bb    123n  45'aaaa'a  aa\  bb

s="ssadf"  print(s)  del s  print(s)

ssadf  ---------------------------------------------------------------------------  NameError                                 Traceback (most recent call last)  <ipython-input-1-3dfd4f621ec7> in <module>        2 print(s)        3 del s  ----> 4 print(s)    NameError: name 's' is not defined

print(x) x3=tuple(x) print(x3) [1, 2, 5, 4, 3, 10, 20, [1, 2]] (1, 2, 5, 4, 3, 10, 20, [1, 2])

print(x3[5],x3[6]) 10 20

1 print(x[7][0]) print(x[7][1]) 1 2