Python – Multiple Column Sort in Tuples
Sometimes, while working with records, we can have a problem in which we need to perform sort operation on one of the columns, and on other column, if equal elements, opposite sort. This kind of problem can occur as application in many domains such as web development. Lets discuss certain ways in which this problem can be solved.
Input : test_list = [(6, 7), (6, 5), (6, 4), (7, 10)]
Output : [(7, 10), (6, 4), (6, 5), (6, 7)]Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.
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Input : test_list = [(10, 7), (8, 5)]
Output : [(10, 7), (8, 5)]
Method #1 : Using sorted() + lambda
The combination of above functions can offer one of the ways to solve this problem. In this, we perform sort using sorted() and order and column manipulation is handled by lambda function.
Python3
# Python3 code to demonstrate working of# Multiple Column Sort in Tuples# Using sorted() + lambda# initializing listtest_list = [(6, 7), (6, 5), (1, 4), (8, 10)]# printing original listprint("The original list is : " + str(test_list))# Multiple Column Sort in Tuples# Using sorted() + lambdares = sorted(test_list, key = lambda sub: (-sub[0], sub[1]))# printing resultprint("The sorted records : " + str(res)) |
The original list is : [(6, 7), (6, 5), (1, 4), (8, 10)] The sorted records : [(8, 10), (6, 5), (6, 7), (1, 4)]
Method #2 : Using itemgetter() + sorted()
This is yet another way in which this task can be performed. In this, we perform the task required for lambda function using itemgetter().
Python3
# Python3 code to demonstrate working of# Multiple Column Sort in Tuples# Using itemgetter() + sorted()from operator import itemgetter# initializing listtest_list = [(6, 7), (6, 5), (1, 4), (8, 10)]# printing original listprint("The original list is : " + str(test_list))# Multiple Column Sort in Tuples# Using itemgetter() + sorted()res = sorted(test_list, key = itemgetter(1))res = sorted(res, key = itemgetter(0), reverse = True)# printing resultprint("The sorted records : " + str(res)) |
The original list is : [(6, 7), (6, 5), (1, 4), (8, 10)] The sorted records : [(8, 10), (6, 5), (6, 7), (1, 4)]
