Can this be made simpler?

Question

This code passed the code coach but was wondering if there was an easier/different way of doing it.

https://sololearn.com/compiler-playground/c2D0h05YuYvB/?ref=app

Answer 1

Your approach with maketrans is a good generalization of the mapping problem, that could even work with more advanced cryptogtaphic scenarios.
but the way you manually construct the dictionary, is pretty ugly.

In this particular task, the following code works too:

print(''.join(map(lambda c: chr(219-ord(c)), message)))

What does it do?
- ord gives the position of each character in the Ascii table
- 219 comes from the position of z (122) and a (97) added
- subtracting the ord of the actual character I achieve the reverse of the alphabet with a simple math operation
- chr converts the number back to character
- combine all letters back to string with join

Answer 2

Tibor Santa
even simpler, no map or lambda. Just use ''.join(generator expression)

#encode
coded = ''.join(chr(219-ord(c)) for c in input().lower())
print(coded)

#decode
decoded = ''.join(chr(219-ord(c)) for c in coded)
print(decoded)

Answer 3

Just another idea:
You could check if ord(c) is in the valid range and if not, leave it "untranslated". It's just a little add-on, but makes the code more robust.

Answer 4

Interesting.
How about replacing line 3 with the code below?

mapping_table = dict()
# lowercase
for i in range(26):
mapping_table[chr(97 + i)] = chr(97 + 25 - i)

# uppercase
for i in range(26):
mapping_table[chr(65 + i)] = chr(65 + 25 - i)

Or with these lines of code?

import string
mapping_table= dict()
# lowercase
for i in range(26):
mapping_table[string.ascii_lowercase[i]] = string.ascii_lowercase[::-1][i]

# uppercase
for i in range(26):
mapping_table[string.ascii_uppercase[i]] = string.ascii_uppercase[::-1][i]

Answer 5

I just learned str.maketrans is intended to work with str.translate.

It is a little code. Just for fun.

https://sololearn.com/compiler-playground/cTvvnXm7Xl6U/?ref=app

Answer 6

Bob_Li nice :)
I am getting used to other forms of looping too much and "for" is getting erased from my vocabulary :)

Answer 7

lee harding
something like this:
challenge: can coded snd decoded be written as one liners?

https://sololearn.com/compiler-playground/cRcaJH6qgIhO/?ref=app

Answer 8

Thank you for taking the time to reply, being a beginner, any advice is much appreciated. You're right in saying my code is.... on the noob side, it was a pain typing it all out. I'll have to do some research into both of your answers as I'm unfamiliar with either at the moment.

Answer 9

Thank you for the responses everyone. After researching what all of you've said I can safely say I know a bit more than yesterday. I've got 1 question though, how would you stop it translating any white space in the input string if using ord() chr() method?

Answer 10

lee harding
you can add an if statement.

Answer 11

I see, I tried that but couldn't get it to work. I'll keep playing but I may end up coming back to you!