how does indexing work in a for loop when appending a list?-CodePudding

I´m trying write a function that returns a list with the positions for each capital letter it doesn’t work with when the capital letter in the string is repeated.

def capital_indexes(word):
    cap = []
    for i in word:
        if i == i.upper():
            cap.append(word.index(i))
    return cap

print(capital_indexes("HelloWorld"))

[0, 5]

print(capital_indexes("HoHoHoHo"))

[0, 0, 0, 0]

CodePudding user response：

I think that index method is returning the first occurrence of character.

Maybe you should control the index of letter by an another var like this:

def capital_indexes(word):
    cap = []
    index = 0
    for i in word:
        if i == i.upper():
            cap.append(index)
        index=index 1
    return cap

CodePudding user response：

It doesn't work as expected because the indexmethod returns the first occurrence of the match (some docs here).

So... Let's say your code finds the third H (for instance) in the string HoHoHoHo. Then index asks "Hey, give me the first H" Which happens on position 0 (HoHoHoHo).

I suggest you print what you are iterating over. I say this because the fact that you're calling your item i (usually used for indices) makes me think that maaaaaybe there's a tiny confusion between the index and the element?.

Maybe just renaming your control variable will help a bit:

def capital_indexes(word):
    cap = []
    for letter in word:
        if letter == letter.upper():
            cap.append(word.index(letter))
    return cap

With that in mind, you can now take a look to enumerate, which will give you both the item and the position it's in:

def capital_indexes(word):
    cap = []
    for idx, letter in enumerate(word):
        if letter == letter.upper():
            cap.append(idx)
    return cap

If you want to stick to indices, you have to retrieve the contents of position idx in the string:

def capital_indexes(word):
    cap = []
    for idx in range(len(word)):
        letter = word[idx]
        if letter == letter.upper():
            cap.append(idx)
    return cap