python 基础系列09-推导式

梦里梦外; 2023-07-06 06:30 26阅读 0赞

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz_size_16_color_FFFFFF_t_70 2][]

# python 基础系列09-推导式
    
    # 引入sys库
    import sys
    import copy
    from functools import reduce
    
    if __name__ == '__main__':
        mylist = [1,2,3,4]
        # var * var 代表操作
        new_list = [var * var for var in  mylist]
        print(new_list) #[1, 4, 9, 16]
    
        #还可以过滤
        new_list2 = [var * var for var in mylist if var != 3]
        #注意
        new_list3 = (var * var for var in mylist if var != 3)
        print(new_list3)
        print(new_list3.__next__()) #取第一个值
        print(new_list3.__next__())
        print(new_list3.__next__())
    
        mylist2 = [1, 2, 3, 4]
        mydict = {var: 'a' for var in mylist2} #{1: 'a', 2: 'a', 3: 'a', 4: 'a'}
        print(mydict)
        mydict = {var: 'a' for var in mylist2 if var > 3}
    
        #集合操作
        myset = {var+1 for var in mylist2 }
        print(myset)

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200217031335172.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/202002170318176.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/2020021703204753.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxODY2Nzkz,size_16,color_FFFFFF,t_70