Why is this program returning None?

Question

How can I create a Python custom function to get list of strings having length more than a number n when we pass number n and list of strings?

I tried using this function but it returns None:

lst=['shiva', 'patel', 'ram','krishna', 'bran']
filtered_list=[]
def word_remove(n, lst):
    for i in lst:
        if len(i)>n:
            return filtered_list.append(i)
print(word_remove(4,lst))

The output is :

None

Read the documentation on the `append` method. Compare it with `extend`, and other methods of adding a member to a list. — Prune, Jan 04 '21 at 05:23

score 1 · Answer 1 · answered Jan 04 '21 at 05:20

1

append method on a list does not return any value. Hence the None type.

answered Jan 04 '21 at 05:20

MjZac

3,303
1
20
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score 0 · Answer 2 · answered Jan 04 '21 at 05:21

0

Append function has no return type. Try instead this.

def word_remove(n, lst):
    for i in lst:
        if len(i) > n:
            filtered_list.append(i)
    return filtered_list

answered Jan 04 '21 at 05:21

mhhabib

2,733
1
11
22

score 0 · Answer 3 · answered Jan 04 '21 at 05:22

lst = ['shiva', 'patel', 'ram','krishna', 'bran']

filtered_list=[]

def word_remove(n, lst):
    for i in lst:
        if len(i)>n:
            filtered_list.append(i)
    return filtered_list

print (word_remove(4,lst))

Output:

['shiva', 'patel', 'krishna']

The method append does not return anything. So you need to return the whole filtered_list.

Why is this program returning None?

3 Answers3