Sort mixed list in Python

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 sort
def 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() + comparator
test_list.sort(key = mixs)

# printing result
print("List after mixed sorting : " + str(test_list))

Output : 

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 result
print("List after mixed sorting : " + str(res))

Output : 

The original list : ['4', 'gfg', '2', 'best', 'is', '3']
List after mixed sorting : ['2', '3', '4', 'best', 'gfg', 'is']

Method #3 : Using isnumeric(),sort() and extend() methods

Python3

# Python3 code to demonstrate working of
# Sort Mixed List

# initialize list
test_list = ['4', 'gfg', '2', 'best', 'is', '3']

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

# Sort Mixed List
res = []
x=[]
for i in test_list:
    if i.isnumeric():
        res.append(i)
    else:
        x.append(i)
res.sort()
x.sort()
res.extend(x)
# printing result
print("List after mixed sorting : " + str(res))

Output

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)