Python – Assign Alphabet to each element

Given a list of elements, assign similar alphabet to same element.

Input : test_list = [4, 5, 2, 4, 2, 6] 
Output : [‘a’, ‘b’, ‘c’, ‘a’, ‘c’, ‘d’] 
Explanation : Alphabets assigned to elements as occurring.

Input : test_list = [4, 5, 2, 4, 2, 6] 
Output : [‘a’, ‘b’, ‘c’, ‘a’, ‘c’] 
Explanation : Alphabets assigned to elements as occurring. 

Method #1 : Using ascii_lowercase() + loop + list comprehension 

In this, we extract all lowercase alphabets using lowercase(), and create dictionary mapping same element to similar character, post that we flatten that to appropriate index using list comprehension.

Python3

# Python3 code to demonstrate working of
# Assign Alphabet to each element
# Using ascii_lowercase() + loop + list comprehension
import string

# initializing list
test_list = [4, 5, 2, 4, 2, 6, 5, 2, 5]

# printing list
print("The original list : " + str(test_list))

temp = {}
cntr = 0
for ele in test_list:
    if ele in temp:
        continue

    # assigning same Alphabet to same element
    temp[ele] = string.ascii_lowercase[cntr]
    cntr += 1

# flattening
res = [temp.get(ele) for ele in test_list]

# printing results
print("The mapped List : " + str(res))

Output

The original list : [4, 5, 2, 4, 2, 6, 5, 2, 5]
The mapped List : ['a', 'b', 'c', 'a', 'c', 'd', 'b', 'c', 'b']

Method #2 : Using defaultdict() + ascii_lowercase() + iter()

In this we use defaultdict() to assign values to similar elements, ascii_lowercase() is used to get all lowercase all lowercased alphabets.

Python3

# Python3 code to demonstrate working of
# Assign Alphabet to each element
# Using defaultdict() + ascii_lowercase() + iter()
from collections import defaultdict
import string

# initializing list
test_list = [4, 5, 2, 4, 2, 6, 5, 2, 5]

# printing list
print("The original list : " + str(test_list))

# assigning lowercases as iterator
temp = iter(string.ascii_lowercase)

# lambda functions fits to similar elements
res = defaultdict(lambda: next(temp))

# flatten in list
res = [res[key] for key in test_list]

# printing results
print("The mapped List : " + str(list(res)))

Output

The original list : [4, 5, 2, 4, 2, 6, 5, 2, 5]
The mapped List : ['a', 'b', 'c', 'a', 'c', 'd', 'b', 'c', 'b']