Given 2 tuples, perform cross pairing of corresponding tuples, convert to single tuple if 1st element of both tuple matches.
Input : test_list1 = [(1, 7), (6, 7), (8, 100), (4, 21)], test_list2 = [(1, 3), (2, 1), (9, 7), (2, 17)]
Output : [(7, 3)]
Explanation : 1 occurs as tuple element at pos. 1 in both tuple, its 2nd elements are paired and returned.Input : test_list1 = [(10, 7), (6, 7), (8, 100), (4, 21)], test_list2 = [(1, 3), (2, 1), (9, 7), (2, 17)]
Output : []
Explanation : NO pairing possible.
Method #1 : Using list comprehension
In this, we check for 1st element using conditional statements and, and construct new tuple in list comprehension.
Python3
# Python3 code to demonstrate working of # Cross Pairing in Tuple List# Using list comprehension # initializing liststest_list1 = [(1, 7), (6, 7), (9, 100), (4, 21)]test_list2 = [(1, 3), (2, 1), (9, 7), (2, 17)] # printing original listsprint("The original list 1 : " + str(test_list1))print("The original list 2 : " + str(test_list2)) # corresponding loop in list comprehensionres = [(sub1[1], sub2[1]) for sub2 in test_list2 for sub1 in test_list1 if sub1[0] == sub2[0]] # printing result print("The mapped tuples : " + str(res)) |
The original list 1 : [(1, 7), (6, 7), (9, 100), (4, 21)] The original list 2 : [(1, 3), (2, 1), (9, 7), (2, 17)] The mapped tuples : [(7, 3), (100, 7)]
Method #2 : Using zip() + list comprehension
In this, the task of pairing is done using zip() and conditional check is done inside list comprehension.
Python3
# Python3 code to demonstrate working of # Cross Pairing in Tuple List# Using zip() + list comprehension # initializing liststest_list1 = [(1, 7), (6, 7), (9, 100), (4, 21)]test_list2 = [(1, 3), (2, 1), (9, 7), (2, 17)] # printing original listsprint("The original list 1 : " + str(test_list1))print("The original list 2 : " + str(test_list2)) # zip() is used for pairing res = [(a[1], b[1]) for a, b in zip(test_list1, test_list2) if a[0] == b[0]] # printing result print("The mapped tuples : " + str(res)) |
The original list 1 : [(1, 7), (6, 7), (9, 100), (4, 21)] The original list 2 : [(1, 3), (2, 1), (9, 7), (2, 17)] The mapped tuples : [(7, 3), (100, 7)]
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