Detect and replace multiple letters with single letter-CodePudding

Context: In our language (Bahasa - Indonesian language), we tend to repeat letter to stress on something. For example, when we are happy, we say hore. But when we are very happy, we say horeeeeee.

I want to detect and remove this letter repetition. I am using this to detect if a letter is repeated 3 times or more

a = a.replace('(.)\1{3,}', '(.)')

However, this does not work. The repetition is detected but it is not replaced with one letter. Please let me know how to do it.

Thanks

CodePudding user response：

As far as I can tell, python's string replace method does not support regex replacement.

You will want to use the built-in re module.

import re
a=re.sub('(.)\\1{3,}', '\\1',a)

Or if you use raw strings:

import re
a=re.sub(r'(.)\1{3,}', r'\1',a)

CodePudding user response：

You could use the groupby() function from itertools, for example

import itertools

s= 'apa kabarrrrr mass asal manaaaaa'
print(''.join(ch for ch, g in itertools.groupby(s)))

Output

apa kabar mas asal mana

To see the groups for each char one can use list(g)

for k, g in itertools.groupby(s):
     print(k,list(g))

a ['a']
p ['p']
a ['a']
  [' ']
k ['k']
a ['a']
b ['b']
a ['a']
r ['r', 'r', 'r', 'r', 'r']
  [' ']
m ['m']
a ['a']
s ['s', 's']
  [' ']
a ['a']
s ['s']
a ['a']
l ['l']
  [' ']
m ['m']
a ['a']
n ['n']
a ['a', 'a', 'a', 'a', 'a']

CodePudding user response：

Agree with @Michael Sohnen's Answer, just to add, you can also use function to custom replace:

import re


str = 'apa kabarrrrr mass asal manaaaaa';

def replace_func(matches):
    return matches.group()[0];

print(re.sub('(.)\\1{3,}',  replace_func, str)) #apa kabar mass asal mana

This also expands the possibility of customization