列表检查值上的 Python-KeyError 'C'

Question

I am trying to create a code that assigns values to letters in words, and then spit them back out in pythonm. This is my code:

import time
import os
import string
os.system('cls')
values = dict()

for index, letter in enumerate(string.ascii_lowercase):
    values[letter] = index + 1


def scramble(letter):
   i = 0
   phrase = list(letter)
   mylist = []
   while i < len(phrase):
      list.append(values[phrase[i]])
      i = i + 1
   print(res)
   
scramble("Crapx")

Well doing this I get the error

Traceback (most recent call last):
  File "d:\Code\Python\fibbanaci.py", line 22, in <module>
    scramble("Crapx")
  File "d:\Code\Python\fibbanaci.py", line 18, in scramble
    list.append(values[phrase[i]])
KeyError: 'C'
PS D:\Code\Python> 

Does anyone know a fix for this?

Answer 1

The dictionary values map string.ascii_lowercase letters to index + 1. It has no key with upper case letters. Infact, you could do,

def scramble(letter):
   i = 0
   phrase = list(letter.lower())
   mylist = []
   while i < len(phrase):
      mylist.append(values[phrase[i]])
      i += 1
   print(phrase)

or; Even though the values dictionary in the global namespace, as a habit, it is good to introduce variables which will be used inside the function (compound structure) as parameters to the function.

import time
import os
import string

os.system('cls')
values = {letter: index for index, letter in enumerate(string.ascii_lowercase, 1)}

def scramble(letter, values):
    print [values[char] for char in letter.lower()]

scramble("Crapx", values)

Answer 2

Your dictionary doesn't have uppercase keys. You can use string.ascii_letters instead of string.ascii_lowercase .

import time
import os
import string
os.system('cls')
values = dict()

for index, letter in enumerate(string.ascii_letters):
    values[letter] = index + 1

def scramble(letter):
   i = 0
   phrase = list(letter)
   mylist = []
   while i < len(phrase):
      mylist.append(values[phrase[i]])
      i = i + 1
   print(mylist)
   
scramble("Crapx")