Python | Records Intersection

Sometimes, while working with tuples, we can have a problem in which we need similar features of two records. This type of application can come in the Data Science domain. Let’s discuss certain ways in which this problem can be solved. 

Method #1: Using set() + “&” operator This task can be performed using symmetric difference functionality offered by XOR operator over sets. The conversion to set is done by set(). 

The original tuple 1 : (3, 4, 5, 6)
The original tuple 2 : (5, 7, 4, 10)
The similar elements from tuples are : (4, 5)

Method #2: Using intersection() + set() This is a method similar to the above method, the difference is that instead of & operator, we use inbuilt function to perform the task of filtering dissimilar elements.

The original tuple 1 : (3, 4, 5, 6)
The original tuple 2 : (5, 7, 4, 10)
The similar elements from tuples are : (4, 5)

Time complexity: O(n), where n is the length of the longer tuple because we are using the intersection() method of sets to find the common elements.
Auxiliary space: O(n) because we are creating two sets, each of which contains the same number of elements as the corresponding tuple, and a third set to store the common elements.

Method #3: Using Counter

The original tuple 1 : (3, 4, 5, 6)
The original tuple 2 : (5, 7, 4, 10)
The similar elements from tuples are : (4, 5)

This approach uses the Counter class from the collections module to create a counter object for each tuple, and then uses a list comprehension to filter the elements of the first tuple that have the same count in both counter objects. It then converts the resulting list to a tuple. Time complexity is O(n) as it iterates through the first tuple once and creates two counter objects with a time complexity of O(n) each.

Method #4: Using list comprehension and the “in” operator

Use a list comprehension and the “in” operator to find the common elements between the two tuples.

• Create a tuple named test_tup1 containing the values (3, 4, 5, 6).
• Create another tuple named test_tup2 containing the values (5, 7, 4, 10).
• Use a list comprehension to create a new tuple named res containing the elements that are common to both test_tup1 and test_tup2.
• Iterate through each element x in test_tup1.
• Check if x is in test_tup2.
• If x is in test_tup2, add it to the res tuple.
• Convert the res tuple to a string and print it, along with a message stating that it contains the similar elements from the tuples.

The similar elements from tuples are : (4, 5)

Time complexity: O(n*m), where n and m are the lengths of the two input tuples. 
Auxiliary space: O(k), where k is the number of elements that are common to both tuples.

Method 5: Using built-in function filter() + lambda function 

The filter() function takes two arguments, a lambda function and an iterable, and returns a filter object containing only the items from the iterable for which the lambda function returns True. In this case, the lambda function checks if the element of test_tup1 is also present in test_tup2.

1. Two tuples test_tup1 and test_tup2 are initialized with some elements.
2. The original tuples test_tup1 and test_tup2 are printed using the print() function and string concatenation.
3. A new tuple res is created by applying the filter() function on test_tup1. The filter() function is passed a lambda function as its first argument which checks if the element of test_tup1 is also present in test_tup2. The filter() function returns a filter object containing only the common elements between test_tup1 and test_tup2. The tuple() function is applied on this filter object to convert it into a new tuple.
4. The new tuple res containing the common elements between test_tup1 and test_tup2 is printed using the print() function and string concatenation.
5. The program execution ends.

The original tuple 1 : (3, 4, 5, 6)
The original tuple 2 : (5, 7, 4, 10)
The similar elements from tuples are : (4, 5)

Time complexity: This approach has a time complexity of O(n), where n is the length of the smaller tuple.
Auxiliary space: This approach requires O(n) space to store the common elements in a new tuple.

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Article Tags :

• Python
• Python Programs
• Python tuple-programs

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• python