Python – Assign pair elements from Tuple Lists
Given a tuple list, assign with each element, its pair elements from other similar pairs.
Input : test_list = [(5, 3), (7, 5), (8, 4)]
Output : {5: [3], 7: [5], 8: [4], 4: []}
Explanation : 1st elements are paired with respective 2nd elements from all tuples.Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.
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Input : test_list = [(5, 3)]
Output : {5: [3]}
Explanation : Only one tuples, 5 paired with 3.
Method : Using setdefault() + loop
In this, we use brute way to solve this, iterate for each tuple, and set default values for each, key and value as empty list, appending the elements to respective list if already present.
Python3
# Python3 code to demonstrate working of # Assign pair elements from Tuple Lists# Using setdefault + loop # initializing listtest_list = [(5, 3), (7, 5), (2, 7), (3, 8), (8, 4)] # printing stringprint("The original list : " + str(test_list)) # initializing dictionaryres = dict()for key, val in test_list: # adding to both, corresponding keys and values res.setdefault(val, []) res.setdefault(key, []).append(val) # printing results print("The resultant pairings : " + str(res)) |
The original list : [(5, 3), (7, 5), (2, 7), (3, 8), (8, 4)]
The resultant pairings : {3: [8], 5: [3], 7: [5], 2: [7], 8: [4], 4: []}
