When it is required to perform cross pairing in a list of tuples, the ‘zip’ method, a list comprehension and the ‘==’ operator is used.
Example
Below is a demonstration of the same −
my_list_1 = [('Hi', 'Will'), ('Jack', 'Python'), ('Bill', 'Mills'), ('goodwill', 'Jill')]
my_list_2 = [('Hi', 'Band'), ('Jack', 'width'), ('Bill', 'cool'), ('a', 'b')]
print("The first list is : " )
print(my_list_1)
print("The second list is :")
print(my_list_2)
my_list_1.sort()
my_list_2.sort()
print("The first list after sorting is ")
print(my_list_1)
print("The second list after sorting is ")
print(my_list_2)
my_result = [(a[1], b[1]) for a, b in zip(my_list_1, my_list_2) if a[0] == b[0]]
print("The resultant list is : ")
print(my_result)Output
The first list is :
[('Hi', 'Will'), ('Jack', 'Python'), ('Bill', 'Mills'), ('goodwill', 'Jill')]
The second list is :
[('Hi', 'Band'), ('Jack', 'width'), ('Bill', 'cool'), ('a', 'b')]
The first list after sorting is
[('Bill', 'Mills'), ('Hi', 'Will'), ('Jack', 'Python'), ('goodwill', 'Jill')]
The second list after sorting is
[('Bill', 'cool'), ('Hi', 'Band'), ('Jack', 'width'), ('a', 'b')]
The resultant list is :
[('Mills', 'cool'), ('Will', 'Band'), ('Python', 'width')]Explanation
Two list of tuples are defined, and displayed on the console.
Both these lists are sorted in the ascending order, and displayed on the console.
The two list of tuples are zipped and iterated over.
This is done using list comprehension.
Here, the respective elements of both the lists are compared.
If they are equal, they are stored in a list and assigned to a variable.
This is displayed as the output on the console.