I ask for help. There is a task:

https://stepik.org / lesson / Caesar-cipher-23896 / step / 1? adaptive = true & amp; unit = 6422

Caesar’s cipher consists in replacing each character of the input string with a character located several positions to the left or to the right of it in the alphabet.

The shift is the same for all characters. The shift is cyclical, i.e. if a unit shift is applied to the last character of the alphabet, it will be replaced by the first character, and vice versa.

Write a program that encrypts text with the Caesar cipher.

Alphabet used – space and small Latin characters: ‘abcdefghijklmnopqrstuvwxyz’

Input format:
The first line specifies the encryption offset to be used: an integer. A positive number corresponds to a shift to the right. The second line contains a non-empty encryption phrase. Ignore leading and trailing spaces.

Output format:
The only line containing the phrase: Result: “…”, where instead of an ellipsis inside quotes, an encrypted sequence is written.

Sample Input 1:
3
i am caesar
Sample Output 1:
Result: "lcdpcfdhvdu"

So, here’s how I solved it:

a = int (input ())
b = input ()
c = 'abcdefghijklmnopqrstuvwxyz'
res = []
len_c = len (c)
for i in b:
  res.append (c [(c.find (i) + a)% len_c])
print ('Result:', '"', ''. join (res), '"', sep = '')

The interpreter outputs everything correctly. The test does not pass on the site. Please tell me where you went wrong.

Answer 1, authority 100%

My listing for this task:

alpha = 'abcdefghijklmnopqrstuvwxyz'
n = int (input ())
s = input (). strip ()
res = ''
for c in s:
  res + = alpha [(alpha.index (c) + n)% len (alpha)]
print ('Result: "' + res + '"')

In your code, you should add the removal of whitespace at the beginning and end of the line.

Answer 2

# modules
from colorama import *
from pyfiglet import *
init ()
#title
title = figlet_format ('Cesar')
print (Fore.WHITE)
print (title)
print (Fore.GREEN)
#main
while True:
  offset = int (input ('Offset'))
  str = input ('String')
  alphabet = 'abcdefghijklmnopqrstuvwxyz'
  res = []
  ln = len (alphabet)
  n = '. \ / [] {} () = -.,;: \' "1234567890 ~!` @ # $% ^ & amp; * & lt; & gt;? | = + _- '
  for l in str:
    if not l in n:
      res.append (alphabet [(alphabet.find (l) + offset)% ln])
    else:
      res.append (l)
  print (''. join (res))

This code filters out characters