Add string in a certain position

Question

Is there any function in Python that I can use to insert a value in a certain position of a string?

Foe example :

"3655879ACB6" then in position 4 add "=" to become "3655=879ACB6"

Answer 1

Python Strings are immutable.

>>> s='355879ACB6'
>>> s[4:4] = '-'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'str' object does not support item assignment
 

It is, however, possible to create a new string that has the inserted character:

>>> s[:4] + '-' + s[4:]
'3558-79ACB6'