PYTHON

separate each characters by commas into a single characters separated by commas

# E.g: 
# 'hello' -->  'h', 'e', 'l', 'l', 'o'

import regex as re
a = "hello"
b = ','.join(a)  #gives 'h, e, l, l, o'
result = re.split(r",(?![, ])", b)  # this separates each characters separated by commas in b into single string character
print(result)

separate each characters by commas into a single string

>>> ','.join('Hello world')
'H,e,l,l,o, ,w,o,r,l,d'
>>> ','.join(['Hello', 'world'])
'Hello,world'