When it is required to get the count of the unique values in a list of tuple, ‘defaultdict’, ‘set’ operator and the ‘append’ method are used.
Example
Below is a demonstration of the same −
from collections import defaultdict
my_list = [(12, 32), (12, 21), (21, 32), (89, 21), (71, 21), (89, 11), (99, 10), (8, 23), (10, 23)]
print("The list is :")
print(my_list)
my_result = defaultdict(list)
for element in my_list:
my_result[element[1]].append(element[0])
my_result = dict(my_result)
result_dictionary = dict()
for key in my_result:
result_dictionary[key] = len(list(set(my_result[key])))
print("The resultant list is :")
print(result_dictionary)Output
The list is :
[(12, 32), (12, 21), (21, 32), (89, 21), (71, 21), (89, 11), (99, 10), (8, 23), (10, 23)]
The resultant list is :
{32: 2, 21: 3, 11: 1, 10: 1, 23: 2}Explanation
The required packages are imported into the environment.
A list of tuple is defined and is displayed on the console.
An empty dictionary is created.
The list is iterated over, and the second and first elements are appended to the dictionary.
This list is again converted to a dictionary.
Another empty dictionary is created.
The list is iterated over, and unique elements are obtained using ‘set’ operator.
It is converted to a list, and its length is assigned to a variable.
This is the output that is displayed on the console.