python - Why won't my caesar shift work properly? -

this code:

text = input("what's text:  ") shift = int(input("what's shift: "))  def caesar_shift(text, shift):     cipher = ""     in text:         if i.isalpha():             stayin = ord(i) + shift             if stayin > ord('z'):                 stayin -= 26             lastletter = chr(stayin)         cipher += lastletter          print("your ciphertext is: ", cipher)      return cipher  caesar_shift(text, shift) 

when run it, , example, test hello world, , shift 1, get:

what's text:  hello world what's shift: 1 ciphertext is:  ciphertext is:  if ciphertext is:  ifm ciphertext is:  ifmm ciphertext is:  ifmmp ciphertext is:  ifmmpp ciphertext is:  ifmmppx ciphertext is:  ifmmppxp ciphertext is:  ifmmppxps ciphertext is:  ifmmppxpsm ciphertext is:  ifmmppxpsme 

why this? doing wrong, in advance!

you

if i.isalpha(): 

but have no else-clause if. means add last letter when not letter. hence ifmmpp instead of ifmmp hello.

that bit should changed to:

if i.isalpha():     stayin = ord(i) + shift     if stayin > ord('z'):         stayin -= 26     lastletter = chr(stayin)     cipher += lastletter else:     cipher += 

if don't want result printed out once every loop, move outside loop.