How do I remove spaces in a string using a loop in python?

Your code is stopping after the first space is replaced because you've told it to. You have return s inside the loop, and when that is reached, the rest of the loop is abandoned since the function exits. You should remove that line entirely.

There's another issue though, related to how you're indexing. When you iterate on range(len(s)) for your indexes, you're going to go to the length of the original string. If you've removed some spaces, however, those last few indexes will no longer be valid (since the modified string is shorter). Another similar issue will come up if there are two spaces in a row (as in "foo bar"). Your code will only be able to replace the first one. After the first space is removed, the second spaces will move up and be at the same index, but the loop will move on to the next index without seeing it.

You can fix this in two different ways. The easiest fix is to loop over the indexes in reverse order. Removing a space towards the end won't change the indexes of the earlier spaces, and the numerically smallest indexes will always be valid even as the string shrinks.

def onlyLetters(s):
    for i in range(len(s)-1, -1, -1): # loop in reverse order
        if s[i] == " ":
            s = s[:i] + s[i+1:]
    return s

The other approach is to abandon the for loop for the indexes and use a while loop while manually updating the index variable:

def onlyLetters(s):
    i = 0
    while i < len(s):
        if s[i] == " ":
            s = s[:i] + s[i+1:]
        else:
            i += 1
    return s

just use python replace() method for Strings.

s.replace(" ","")

If you want to remove all spaces, use str.replace():

sentence = ' Freeman was here'
sentence.replace(" ", "")
>>> 'Freemanwashere'

If you want to remove leading and ending spaces, use str.strip():

sentence = ' Freeman was here'
sentence.strip()
>>> 'Freeman was here'

If you want to remove duplicated spaces, use str.split():

sentence = ' Freeman was here'
" ".join(sentence.split())
>>> 'Freemanwashere'

If you also want to remove all the other strange whitespace characters that exist in unicode you can use re.sub with the re.UNICODE arguement:

text = re.sub(r"\s+", "", text, flags=re.UNICODE)

or something like this,it's handles any whitespace characters that you're not thinking of 😉 :

>>> import re
>>> re.sub(r'\s+', '', 'Freeman was here')
'Freemanwashere'

if you don’t want to use anything like replace() or join() etc. you can do this :

def filter(input):
    for i in input:
        yield " " if i in " ,.?!;:" else i

def expand(input):
    for i in input:
        yield None if i == " " else object(), i

def uniq(input):
    last = object()
    for key, i in input:
        if key == last:
            continue
        yield key, i

def compact(input):
    for key, i in input:
        yield i

yourText = compact(uniq(expand(filter(input()))))

It's a little hard to tell, because the indentation in your example is hard to understand. But it looks to me like after you encounter and remove the very first space, you are returning s. So you only get a chance to remove one space before returning.

Try only returning s once you are out of the for loop.

You can do s.replace(" ", ""). This will take all your spaces (" ") and replace it by nothing (""), effectively removing the spaces.

You're returning the function after the first occurrence of a ",", which means it exits the loop and the function altogether. That's why it's only working for the first comma.

Try this,

def onlyLetters(s):
   length=len(s)
   i=0
   while(i<length):

      if s[i] == " ":
         s = s[:i] + s[i+1:]
         length=len(s)
      else
         i+=1

   return s

If you want to use your own code only then try running this:

def onlyLetters(s):
    for i in range(len(s)):
        if s[i] == " ":
           s = s[:i] + s[i+1:]
    return s

or better you may use:

def onlyLetters(s):
    return s.replace(" ","")

def remove_spaces(text):
    text_with_out_spaces='';
    while text!='':
        next_character=text[0];
        if next_character!=' ':
            text_with_out_spaces=text_with_out_spaces +next_character;
        text=text[1:];
    return text_with_out_spaces

print remove_spaces("Hi Azzam !! ?");