字符串常用功能和列表元组的基本操作

字符串的常用功能&＃xff1a;

1.移除空白

2.分割

3.长度

4.索引

5.切片

例&＃xff1a;

1.移除空白&＃xff0c;在代码后面加入.strip(),也可以在括号里添加想要去除的代码

name &＃61; input("name:").strip()
age &＃61; int(input("age:"))
job &＃61; input("job:")

msg&＃61;&＃39;&＃39;&＃39;Infomation of %s:
    name:   %s
    age:    %d
    job:    %s
&＃39;&＃39;&＃39;%(name,name,age,job)
print(msg)

name:             panzhonglv
age:        22
job:        it
Infomation of panzhonglv:
    name:   panzhonglv
    age:    22
    job:            it

列表的基本操作&＃xff1a;

dir(name_list)
[&＃39;__add__&＃39;, &＃39;__class__&＃39;, &＃39;__contains__&＃39;, &＃39;__delattr__&＃39;, &＃39;__delitem__&＃39;, &＃39;__dir__&＃39;, &＃39;__doc__&＃39;, &＃39;__eq__&＃39;, &＃39;__format__&＃39;, &＃39;__ge__&＃39;, &＃39;__getattribute__&＃39;, &＃39;__getitem__&＃39;, &＃39;__gt__&＃39;, &＃39;__hash__&＃39;, &＃39;__iadd__&＃39;, &＃39;__imul__&＃39;, &＃39;__init__&＃39;, &＃39;__iter__&＃39;, &＃39;__le__&＃39;, &＃39;__len__&＃39;, &＃39;__lt__&＃39;, &＃39;__mul__&＃39;, &＃39;__ne__&＃39;, &＃39;__new__&＃39;, &＃39;__reduce__&＃39;, &＃39;__reduce_ex__&＃39;, &＃39;__repr__&＃39;, &＃39;__reversed__&＃39;, &＃39;__rmul__&＃39;, &＃39;__setattr__&＃39;, &＃39;__setitem__&＃39;, &＃39;__sizeof__&＃39;, &＃39;__str__&＃39;, &＃39;__subclasshook__&＃39;, &＃39;append&＃39;&＃xff08;追加&＃xff09;, &＃39;clear&＃39;&＃xff08;清空列表&＃xff09;, &＃39;copy&＃39;&＃xff08;拷贝&＃xff09;, &＃39;count&＃39;&＃xff08;&＃xff08;统计&＃xff09;&＃xff09;, &＃39;extend&＃39;&＃xff08;扩展&＃xff09;, &＃39;index&＃39;&＃xff08;索引&＃xff09;, &＃39;insert&＃39;&＃xff08;插入&＃xff09;, &＃39;pop&＃39;&＃xff08;删除&＃xff09;, &＃39;remove&＃39;&＃xff08;删除指定的一个&＃xff09;, &＃39;reverse&＃39;&＃xff08;反转&＃xff09;, &＃39;sort&＃39;&＃xff08;排序&＃xff09;]

>>> name_list &＃61; [&＃39;alex&＃39;,&＃39;panzl&＃39;,&＃39;chaoge&＃39;,&＃39;aoyun&＃39;]
>>> name_list
[&＃39;alex&＃39;, &＃39;panzl&＃39;, &＃39;chaoge&＃39;, &＃39;aoyun&＃39;]

取出&＃39;panzl&＃39;&＃xff0c;在取出&＃39;aoyun&＃39;,在取出&＃39;alex&＃39;

>>> name_list[1]
&＃39;panzl&＃39;

>>> name_list[3]
&＃39;aoyun&＃39;
>>> name_list[0]
&＃39;alex&＃39;

列表相对于变量的好处&＃xff1a;可以存多个信息&＃xff0c;变量一般只存一个字符串一个数字&＃xff0c;信息量有限&＃xff0c;通过列表可以存多个&＃xff0c;变量虽然可以存多个变量&＃xff0c;但是不能单独取出&＃xff0c;无法调用

PYTHON中每个元素都会对应一个编号&＃xff0c;也就是下标&＃xff0c;当在列表中取值时&＃xff0c;通过对应的下标&＃xff0c;就可以取出来。

追加 append

例&＃xff1a;

>>> name_list.append(&＃39;hongwei&＃39;)
>>> name_list
[&＃39;alex&＃39;, &＃39;panzl&＃39;, &＃39;chaoge&＃39;, &＃39;aoyun&＃39;, &＃39;hongwei&＃39;]
>>> name_list.append(&＃39;panzl&＃39;)  #还可以添加重名
>>> name_list
[&＃39;alex&＃39;, &＃39;panzl&＃39;, &＃39;chaoge&＃39;, &＃39;aoyun&＃39;, &＃39;hongwei&＃39;, &＃39;panzl&＃39;]

索引

把列表中panzl取出来&＃xff0c;很简单&＃xff0c;但当列表有5000个&＃xff0c;甚至更多是&＃xff0c;就需要找到对应的索引值

比如我们要找&＃39;panzl&＃39;的索引值时就可以&＃xff1a;

>>> name_list.index(&＃39;panzl&＃39;)
1

找到了&＃xff0c;index就会显示最先找到的那个也就是1,但是它只返回了一个&＃xff0c;但后面还有一个&＃xff0c;那这时就要通过count来统计

>>> name_list.count(&＃39;panzl&＃39;)
2

 插入  insert

比如在&＃39;panzl&＃39;后面插入另一个字符串

例如&＃xff1a;

>>> name_list.insert(2,&＃39;jibw&＃39;)
>>> name_list
[&＃39;alex&＃39;, &＃39;panzl&＃39;, &＃39;jibw&＃39;, &＃39;chaoge&＃39;, &＃39;aoyun&＃39;, &＃39;hongwei&＃39;, &＃39;panzl&＃39;]

删除

pop是从最后一个开始删除

>>> name_list
[&＃39;alex&＃39;, &＃39;panzl&＃39;, &＃39;jibw&＃39;, &＃39;chaoge&＃39;, &＃39;aoyun&＃39;, &＃39;hongwei&＃39;, &＃39;panzl&＃39;]
>>> name_list.pop()
&＃39;panzl&＃39;
>>> name_list
[&＃39;alex&＃39;, &＃39;panzl&＃39;, &＃39;jibw&＃39;, &＃39;chaoge&＃39;, &＃39;aoyun&＃39;, &＃39;hongwei&＃39;]

li &＃61; list([1,2,3])
print(li)
ret &＃61; li.pop(0)
print(li)
print(ret)

结果
[1, 2, 3]
[2, 3]
1

remove是指定删除一个

>>> name_list.remove(&＃39;jibw&＃39;)
>>> name_list
[&＃39;alex&＃39;, &＃39;panzl&＃39;, &＃39;chaoge&＃39;, &＃39;aoyun&＃39;, &＃39;hongwei&＃39;]
>>>

如何把指定删除多个相同的元素&＃xff0c;比如删除&＃39;aoyun&＃39;

>>> name_list.insert(5,&＃39;aoyun&＃39;)
>>> name_list.insert(2,&＃39;aoyun&＃39;)
>>> name_list
[&＃39;alex&＃39;, &＃39;aoyun&＃39;, &＃39;aoyun&＃39;, &＃39;chaoge&＃39;, &＃39;hongwei&＃39;, &＃39;panzl&＃39;, &＃39;aoyun&＃39;]

>>> for i in range(name_list.count(&＃39;aoyun&＃39;)):
    name_list.remove(&＃39;aoyun&＃39;)

反转 reverse

>>> name_list
[&＃39;alex&＃39;, &＃39;panzl&＃39;, &＃39;chaoge&＃39;, &＃39;aoyun&＃39;, &＃39;hongwei&＃39;]
>>> name_list.reverse()
>>> name_list
[&＃39;hongwei&＃39;, &＃39;aoyun&＃39;, &＃39;chaoge&＃39;, &＃39;panzl&＃39;, &＃39;alex&＃39;]

sort 排序&＃xff0c;根据ASCLL码来排序的

>>> name_list
[&＃39;hongwei&＃39;, &＃39;aoyun&＃39;, &＃39;chaoge&＃39;, &＃39;panzl&＃39;, &＃39;alex&＃39;]
>>> name_list.sort()
>>> name_list
[&＃39;alex&＃39;, &＃39;aoyun&＃39;, &＃39;chaoge&＃39;, &＃39;hongwei&＃39;, &＃39;panzl&＃39;]

切片

>>> a &＃61; [1,2,3,&＃39;a&＃39;,&＃39;b&＃39;]
>>> a
[1, 2, 3, &＃39;a&＃39;, &＃39;b&＃39;]
>>> a.sort()
Traceback (most recent call last):
  File "", line 1, in
    a.sort()
AttributeError: &＃39;tuple&＃39; object has no attribute &＃39;sort&＃39;
>>> a.insert(1,6)
>>> a
[1, 6, 2, 3, &＃39;a&＃39;, &＃39;b&＃39;]

>>> a[0:2]   #顾首不顾尾
[1, 6]
>>> a.insert(3,4)
>>> a
[1, 6, 2, 4, 3, &＃39;a&＃39;, &＃39;b&＃39;]

>>> a[1:5:3]    #跳着切片
[6, 3]

>>> a[-2:] #倒着切片
[&＃39;a&＃39;, &＃39;b&＃39;]

>>> b &＃61; a[0:5]   #在python3中sort排序数字和字符串一起会报错&＃xff0c;我们可以用切片方式分开
>>> b
[1, 6, 2, 4, 3]
>>> b.sort()
>>> b
[1, 2, 3, 4, 6]

长度

extend   扩展列表

>>> a.extend(b)
>>> a
[1, 6, 2, 4, 3, &＃39;a&＃39;, &＃39;b&＃39;, 1, 2, 3, 4, 6]

循环

包含

>>> a &＃61; [1,6,2,4,3,&＃39;a&＃39;,&＃39;b&＃39;,1,2,3,4,6]
>>> a
[1, 6, 2, 4, 3, &＃39;a&＃39;, &＃39;b&＃39;, 1, 2, 3, 4, 6]
>>> 4 in a
True          #判断4是否在a中&＃xff0c;True就为真

元组  &＃xff08;元组能做的事&＃xff0c;列表都能做&＃xff0c;实际意义在于希望别人不要改&＃xff09;

>>> t &＃61; (1,2,3,4)

(1, 2, 3, 4)
>>> dir(t)
[&＃39;__add__&＃39;, &＃39;__class__&＃39;, &＃39;__contains__&＃39;, &＃39;__delattr__&＃39;, &＃39;__dir__&＃39;, &＃39;__doc__&＃39;, &＃39;__eq__&＃39;, &＃39;__format__&＃39;, &＃39;__ge__&＃39;, &＃39;__getattribute__&＃39;, &＃39;__getitem__&＃39;, &＃39;__getnewargs__&＃39;, &＃39;__gt__&＃39;, &＃39;__hash__&＃39;, &＃39;__init__&＃39;, &＃39;__iter__&＃39;, &＃39;__le__&＃39;, &＃39;__len__&＃39;, &＃39;__lt__&＃39;, &＃39;__mul__&＃39;, &＃39;__ne__&＃39;, &＃39;__new__&＃39;, &＃39;__reduce__&＃39;, &＃39;__reduce_ex__&＃39;, &＃39;__repr__&＃39;, &＃39;__rmul__&＃39;, &＃39;__setattr__&＃39;, &＃39;__sizeof__&＃39;, &＃39;__str__&＃39;, &＃39;__subclasshook__&＃39;, &＃39;count&＃39;, &＃39;index&＃39;]

元组和列表之间的转换

>>> type(t)

>>> list(t)
[1, 2, 3, 4]
>>> tuple(a)
(1, 6, 2, 4, 3, &＃39;a&＃39;, &＃39;b&＃39;, 1, 2, 3, 4, 6)
>>> list(a)
[1, 6, 2, 4, 3, &＃39;a&＃39;, &＃39;b&＃39;, 1, 2, 3, 4, 6]