Where I am doing wrong

Question

1. A simple substitution code codes 'a' as 1, 'b' as 2, ..., 'z' as 26. Write a function called "encode" that takes in a string, and prints the coded text. The output should be a string, with letters separated by ".". Use "999" for punctuation and spaces. For example, encode("Hello!") should print out "8.5.12.12.15.999".

Ans)

import string
def encode(letter):
    letter=a,b=1,2
    Nums = range(len(letter))
    New_num = []
    for x in Nums:
         New_num.append(x+1)
         mapping = dict(zip(letter, New_num))
    for letter in letterlist:
        if letter in mapping:
            print(mapping[letter],".",sep="",end="")
        else:
            print("999",".",sep="",end="")
    
encode("Hello!")

Answer 1

Hello @Sana,

Lines 3, 6-8 look very sketchy.Here is the solution how to do that:

def encode(s):
    a,z = ord("a"), ord("z")
    return ".".join(
        str(ord(c) - a + 1)
        if ord(c) in range(a, z + 1) else "999"
        for c in s.lower()
    )
print(encode("Hello!"))

To be more simple You can try this also:

def encode(strings):
    import string
   
    s=''
    d={}
    for i in string.ascii_lowercase:
        d[i]=str(ord(i)-96)
    d[' ']='999'
    d['!']='999'
    s=''
    for i in strings.lower():
        s+=d.get(i,i)+'.'
    return s[0:-1]
    
print(encode("Hello!"))