python学习笔记之---多种方式实现list去重

1.set：set去重的前提是，里面的值必须是不可变的数据类型，

           可以把元素编程字符串后来做，也可以用eval()

           ["[1,23]","[1,23]"]

2.dict fromkeys 字典的key

3.循环：添加的方式，删除的方式

   涉及的知识点：引用赋值，深浅拷贝

 

list_a =[1,1,1,2,3]
list_b =list_a.copy()
for i in list_a:
    n =list_a.count(i)
    for j in range(n-1):
        list_b.remove(i)

 

 

>>> a= ["huhongqiang","zhangsan","lisi","wangwu","wuda","ziliao"]
>>> [repr(a).count(i) for i in a]
[1, 1, 1, 1, 1, 1]
>>> [repr(a).count(i[0]) for i in a]
[3, 2, 2, 3, 3, 2]
>>> ["%s:%s" %(i[0],repr(a).count(i[0])) for i in a]
['h:3', 'z:2', 'l:2', 'w:3', 'w:3', 'z:2']