Python表达式的输出含义

盐焗小星球

We initialise the variable ns = [1,2,3,4]
What is the output of the following Python expressions?
a. list(map(lambda x : 2*x+1,ns))
b. list(filter(lambda x : x%2 == 1,ns))
c. [2*x for x in ns if x%2 == 0]
d. [x+y for x in [1,2] for y in [4,6]]
e. [x+y for x in [4,6] for y in [1,2]]

我们初始化变量ns = [1,2,3,4] 。
以下Python表达式的输出是什么？