参考博文
https://blog.csdn.net/weixin_44551646/article/details/109549874

示例1 

def add(a):return a+1def main():list = [1,2,3,4,5]xs = [add(a) for a in list]print(xs)if __name__ == '__main__':main()

Ouput：[2, 3, 4, 5, 6]

1. 先执行for a in list，将每个遍历出的a放到add()函数内
2. 返回出所有经过add()函数后的值

示例2
所有值转换为字符串

ls1 = ['a', 1, 'b', 2]
test2 = [str(i) for i in ls1]
print(test2)

 Output：[‘a’, ‘1’, ‘b’, ‘2’]