How do I find the position of a word in a list using a function?

Question

I know this question was asked many times on here, but could not find an adequate answer.

I need to find the position of the words in a list, when I run my code it gives me None

Here is the code:

words = ['Banana', 'Banana', 'Apple', 'Apple', 'Pear', 'Peach', 'Grapefruit', 'St', 'Apple']

def get_position(words, type_word):
    for idx, value in enumerate(words):
        if value in words == type_word:
            return idx
        

positions = get_position(words, 'Apple')
print(positions)

Preferred Output:

[2, 3, 8]

`if value in words == type_word` is the wrong way to do it. You're already iterating over `words`, so you _know_ value is in the list. Just use `if value == type_word`. — John Gordon, Apr 18 '21 at 00:18

sahasrara62 · Answer 1 · 2021-04-18T09:20:14.123

0

if you use return then function will return the value you want to give back. same is happening here in your code, it is returning the first matched value and not checking further.

either use yield or a temporay list where you saved match result and then return back

def get_position(words, type_word):
    for idx, value in enumerate(words):
        if value == type_word:
            yield idx

or

def get_position(words, type_word):
    matched = []
    for idx, value in enumerate(words):
        if value == type_word:
            matched.append(idx)
    return matched

edited Apr 18 '21 at 09:20

answered Apr 18 '21 at 00:16

sahasrara62

10,069
3
29
44

`if value in words == type_word` is wrong. – John Gordon Apr 18 '21 at 00:23

score 0 · Answer 2 · answered Apr 18 '21 at 00:17

You have to declare an empty list and append the index to the list when you find a match. Then after the loop, you have to return the list. The code will be something like this:

words = ['Banana', 'Banana', 'Apple', 'Apple', 'Pear', 'Peach', 'Grapefruit', 'St', 'Apple']

def get_position(words, type_word):
    ret = []
    for idx, value in enumerate(words):
        if value in words == type_word:
            ret.append(idx)
    return ret
        

positions = get_position(words, 'Apple')
print(positions)

Anmol Parida · Answer 3 · 2021-04-18T00:20:28.997

0

outlist = []
def get_position(words, type_word):
    for idx, value in enumerate(words):
        if value == type_word:
            outlist.append(idx)
    return outlist

edited Apr 18 '21 at 00:20

answered Apr 18 '21 at 00:18

Anmol Parida

672
5
16

The break after `return` is unreachable; moreover, this won't return a list. – augurar Apr 18 '21 at 00:18
@augurar sorry that was draft got submitted, updated. – Anmol Parida Apr 18 '21 at 00:20

score 0 · Answer 4 · answered Apr 18 '21 at 00:21

0

You can use list comprehension.

Use:

def get_position(words, type_word):
    return [idx for idx, w in enumerate(words) if w == type_word]

Output:

>>> get_position(words, "Apple")
[2, 3, 8]

answered Apr 18 '21 at 00:21

Amit Vikram Singh

2,090
10
20

How do I just return a single value and put that code into the function? (In the format of my question)? – Michael Lee Apr 18 '21 at 00:26
You want a list as output. What do you mean by returning a single value? – Amit Vikram Singh Apr 18 '21 at 00:27
Replace `if value in words == type_word` with `if value == type_word`. Your function will now return the index corresponding to the first occurrence of `type_word` in `words`. – Amit Vikram Singh Apr 18 '21 at 00:32

score 0 · Answer 5 · answered Apr 18 '21 at 00:22

Here is another way of solving this issue:

words = ['Banana', 'Banana', 'Apple', 'Apple', 'Pear', 'Peach', 'Grapefruit', 'St', 'Apple']


def get_indexes(lst_from):
    lst = []
    for i in range(len(lst_from)):
        index = lst_from[i:].index('Apple') + i
        if index not in lst:
            lst.append(index)
    
    return lst

How do I find the position of a word in a list using a function?

5 Answers5