使用lambda过滤字符串列表

Question

I have a list like,

old_list=["a_apple","b_banana","c_cherry"]

and I want to get new list using lambda .

new_list=["apple","banana","cherry"]

I tried but it doesn't work as I expected. here is what I wrote.

new_list=filter(lambda x: x.split("_")[1], old_list)

what is the problem ?

Answer 1

Try this:

Python-2 :

In [978]: old_list=["a_apple","b_banana","c_cherry"]

In [980]: new_list = map(lambda x: x.split("_")[1], old_list)

In [981]: new_list
Out[981]: ['apple', 'banana', 'cherry']

Python-3 :

In [4]: new_list = list(map(lambda x: x.split("_")[1], old_list))

In [5]: new_list
Out[5]: ['apple', 'banana', 'cherry']

Answer 2

Using list comprehensions

lst=["a_apple","b_banana","c_cherry"]
[i.split("_")[1] for i in lst]

Output:

['apple', 'banana', 'cherry']

Answer 3

You can map the list with a lambda function:

list(map(lambda s: s.split('_')[1], old_list))

This returns:

['apple', 'banana', 'cherry']

Answer 4

By using lambda and map:

li=["a_apple","b_banana","c_cherry"]

new_li = map(lambda x: x.split('_')[1], li)
print (list(new_li))
# ['apple', 'banana', 'cherry']