replace dosent work python

Question

s = " a a a a "
s = s.replace(" a ", " ")
print (s)

Edit: but when i write s = s.replace("a", " ")
It works fine but also replaces a between words like *package*, so i get *pckge*

I want to replace all a's with space, so i get empty string as an output which has only spaces but i get " a a " as output
Please help fast
And if possible please show me same with python re module, as i have done same with re module but get same result
Re module code:
s = re.sub(" a ", " ", s)

Answer 1

Kairav Bhatia
replace with a pattern of " a ", replaced with "" and a given string of " a a a a " should result in "aa ". This is because the first " a " in the string is replaced then the second a no longer has a space before it and doesn't match. Then the 3rd a matches and is replaced, but now the 4th doesn't have a space before it, so it doesn't match and you're left with the final string of "aa ".
The progression is as follows:
" a a a a "
"a a a "
"aa "
Hope this helps your understanding of what your issue was.

Answer 2

maybe you need to remove the space in the forst argument of replace()?

s = s.replace("a", " ")

this won't be an empty string as it will result with " "

if you want a to remove all a and spaces you either need to use the replace function twice or use a regex that looks like this: "[a ]"

I hope this helps :)

Answer 3

import rel
s='a a a a'
s= s,replace('a',")
print([s])
s= s.replace('a',")
print(s)

This should do it, [a] won't work in python.

Answer 4

SoloProg i have already searched this site but does not help

Answer 5

<★Shaurya Chauhan★>(Inspiration will draw you)
Thanks but in replace line i want
" a " not "a" and also in string i want spaces not commas

Answer 6

Apollo-Roboto thanks but i need spaces in first argument of replace

Answer 7

Apollo-Roboto thanks a lot your regex command worked for me, and can you give me a little explanation about it that why "[a ]" did work and not " a "

Answer 8

I will try sorry for deleting the comment
Because I saw the question then I realized that I had given wrong answer
I will try

Answer 9

It worked but not well, it also removes a between words and i only want to removes a which contains spaces on both sides
Apollo-Roboto

Answer 10

See this now
Kairav Bhatia
is it right
https://code.sololearn.com/cgGaFkMv8dj3/?ref=app

Answer 11

ChaoticDawg but i replace ' a ' with ' ' so it should not be a problem

Answer 12

import re
s = ' a a a a'
s = s.replace(' a', '')
print([s])
s = "package"
s = s.replace(' a', '')
print(s)

s = re.sub(" +a",'', s)
print(s)
This should do it. [ a] won't work.