Sometimes, while working with Python, we can have a problem in which we need to sort a particular list that has mixed data types. That it contains integers and strings and we need to sort each of them accordingly. Let’s discuss certain ways in which this problem can be solved.
Method #1: Using sort() + comparator This problem can be solved using sort functionality provided by Python. We can construct our own custom comparator to complete the task of mixed sort.
Python3
# Python3 code to demonstrate working of# Sort Mixed List# using sort() + comparator# comparator function for sortdef mixs(num): try: ele = int(num) return (0, ele, '') except ValueError: return (1, num, '')# initialize list test_list = [4, 'gfg', 2, 'best', 'is', 3]# printing original list print("The original list : " + str(test_list))# Sort Mixed List# using sort() + comparatortest_list.sort(key = mixs)# printing resultprint("List after mixed sorting : " + str(test_list)) |
The original list : [4, 'gfg', 2, 'best', 'is', 3] List after mixed sorting : [2, 3, 4, 'best', 'gfg', 'is']
Time complexity: O(n*log(n)), where “n” is the number of elements in the list, as sorting the list involves calling the sorting algorithm which has a time complexity of O(n log(n)).
Auxiliary space: O(1), as the sorting is done in place, i.e., no extra memory is used to store a sorted list.
Method #2 : Using sorted() + key + lambda + isdigit() The combination of above functionalities can also be used to achieve solution to this problem. In this, we just sort the list using sorted() using key functionality using lambda function to segregate digits using isdigit().
Python3
# Python3 code to demonstrate working of# Sort Mixed List# using sorted() + key + lambda + isdigit()# initialize list test_list = ['4', 'gfg', '2', 'best', 'is', '3']# printing original list print("The original list : " + str(test_list))# Sort Mixed List# using sorted() + key + lambda + isdigit()res = sorted(test_list, key = lambda ele: (0, int(ele)) if ele.isdigit() else (1, ele))# printing resultprint("List after mixed sorting : " + str(res)) |
The original list : ['4', 'gfg', '2', 'best', 'is', '3'] List after mixed sorting : ['2', '3', '4', 'best', 'gfg', 'is']
Time Complexity: O(n*nlogn) where n is the number of elements in the string list. The sort() + comparator is used to perform the task and it takes O(n*nlogn) time.
Auxiliary Space: O(n) additional space of size n is created where n is the number of elements in the string list.
Method #3 : Using isnumeric(),sort() and extend() methods
Python3
# Python3 code to demonstrate working of# Sort Mixed List# initialize listtest_list = ['4', 'gfg', '2', 'best', 'is', '3']# printing original listprint("The original list : " + str(test_list))# Sort Mixed Listres = []x=[]for i in test_list: if i.isnumeric(): res.append(i) else: x.append(i)res.sort()x.sort()res.extend(x)# printing resultprint("List after mixed sorting : " + str(res)) |
The original list : ['4', 'gfg', '2', 'best', 'is', '3'] List after mixed sorting : ['2', '3', '4', 'best', 'gfg', 'is']
Time Complexity : O(N logN)
Auxiliary Space : O(N)
Method #4: Using two loops
Create an empty list to store the sorted values
Loop through the list and append all the numeric values to a separate list
Loop through the list and append all the non-numeric values to the separate list
Sort both lists
Append the sorted non-numeric list to the sorted numeric list
Return the sorted list
Compute the time and auxiliary space complexity
Python3
# Python3 code to demonstrate working of# Sort Mixed List# initialize listtest_list = ['4', 'gfg', '2', 'best', 'is', '3']# printing original listprint("The original list : " + str(test_list))# Sort Mixed Listnumeric_list = []non_numeric_list = []for i in test_list: if i.isnumeric(): numeric_list.append(int(i)) else: non_numeric_list.append(i) numeric_list.sort()non_numeric_list.sort()sorted_list = []sorted_list.extend([str(i) for i in numeric_list])sorted_list.extend(non_numeric_list)# printing resultprint("List after mixed sorting : " + str(sorted_list)) |
The original list : ['4', 'gfg', '2', 'best', 'is', '3'] List after mixed sorting : ['2', '3', '4', 'best', 'gfg', 'is']
The time complexity of this approach is O(n log n) because of the two sorting operations, one for the numeric list and one for the non-numeric list.
The auxiliary space complexity is also O(n) because of the separate lists created for the numeric and non-numeric values.
