Change each character in string to the next character in alphabet

Question

I am coding in Python 2.7 using PyCharm on Ubuntu.

I am trying to create a function that will take a string and change each character to the character that would be

Answer 1

There's two issues with the code. Instead of looping letters you're looping over numbers since you're calling range(len(str)). The second issue is that within the loop you assign a string to new_word which will cause the next iteration to fail since string doesn't have method append. If you make the following changes it should work:

for letter in str: # for letter in range(len(str)):
    if letter == "z":
        new_word.append("a")
    else:
        new_word.append(ab_st[str.index(letter) + 1])
    # new_word = "".join(new_word)
new_word = "".join(new_word)