Python – Sort List items on basis of their Digits
Given List of elements, perform sorting on basis of digits of numbers.
Input : test_list = [434, 211, 12, 3]
Output : [12, 211, 3, 434]
Explanation : 3 < 12, still later in list, as initial digit, 1 < 3. Hence sorted by digits rather than number.Input : test_list = [534, 211, 12, 7]
Output : [12, 211, 534, 7]
Explanation : 7 < 534, still later in list, as initial digit, 5 < 7. Hence sorted by digits rather than number.
Method #1 : Using map() + str() + ljust() + sorted()
In this, the list elements are converted into string using map() and str(), ljust() is used to append constant character to make each number equal length. Then sort is performed using sorted().
Python3
# Python3 code to demonstrate working of # Sort List by Digits# Using map() + str() + ljust() + sorted() # initializing listtest_list = [434, 211, 12, 54, 3] # printing original listprint("The original list is : " + str(test_list)) # converting elements to string temp1 = map(str, test_list) # getting max lengthmax_len = max(map(len, temp1)) # performing sort operationres = sorted(test_list, key = lambda idx : (str(idx).ljust(max_len, 'a'))) # printing result print("List after sorting : " + str(res)) |
The original list is : [434, 211, 12, 54, 3] List after sorting : [12, 211, 3, 434, 54]
Method #2 : Using list comprehension + sorted() + lambda
In this, we as parameter to sorted(), pass a list of digits. Performing sort according to that gives desired results.
Python3
# Python3 code to demonstrate working of # Sort List by Digits# Using list comprehension + sorted() + lambda # initializing listtest_list = [434, 211, 12, 54, 3] # printing original listprint("The original list is : " + str(test_list)) # performing sort operation# converting number to list of Digitsres = sorted(test_list, key = lambda ele: [int(j) for j in str(ele)]) # printing result print("List after sorting : " + str(res)) |
The original list is : [434, 211, 12, 54, 3] List after sorting : [12, 211, 3, 434, 54]
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