python insert string value into string code example

Example 1: insert value in string python

>>> shepherd = "Martha"
>>> age = 34
>>> # Note f before first quote of string
>>> stuff_in_string = f"Shepherd {shepherd} is {age} years old."
>>> print(stuff_in_string)
Shepherd Martha is 34 years old.

Example 2: insert into string python

def insert (source_str, insert_str, pos):
    return source_str[:pos]+insert_str+source_str[pos:]