In this HackerRank Mutations problem, you need to read a given string, change the character at a given index and then print the modified string.

HackerRank Mutations in python problem solution

HackerRank Mutations in python problem solution

# Enter your code here. Read input from STDIN. Print output to STDOUT
s = raw_input().strip()
i, c = raw_input().strip().split(" ")
s = s[:int(i)] + c + s[int(i) + 1:]
print s

Second solution

s = input()
ic = input()
i, c = ic.split()
i = int(i)
s = s[:i]+c+s[i+1:]
print(s)