itertools:
From itertools import product: itertools is a Python package that provides several functions that work on iterators to generate complicated iterators. This module functions as a fast, memory-efficient tool that can be used alone or in combination to construct iterator algebra.
The key feature of itertools is that its functions are utilized to generate memory-efficient and exact code.
In this article, we will look at itertools. product(), which is a combinatorics generator. This tool is used to calculate the Cartesian Product of two sets and to identify all possible pairs in the form of a tuple (x,y), where x belongs to one set and y belongs to another. Cartesian products can also be achieved with a for loop, although they are less efficient and more difficult to code than itertools.
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Examples:
Example1:
Input:
Given First List =[4, 19, 11, 5] Given Second List=[10, 9, 8, 6, 5, 3]
Output:
The Cartesian Product of the two lists : [(4, 10), (4, 9), (4, 8), (4, 6), (4, 5), (4, 3), (19, 10), (19, 9), (19, 8), (19, 6), (19, 5), (19, 3), (11, 10), (11, 9), (11, 8), (11, 6), (11, 5), (11, 3), (5, 10), (5, 9), (5, 8), (5, 6), (5, 5), (5, 3)]
Example2:
Input:
Given First List=['hello', 'this', 'is', 'btechgeeks'] Given Second List =['sky', 'is', 'blue']
Output:
The Cartesian Product of the two lists :
[('hello', 'sky'), ('hello', 'is'), ('hello', 'blue'), ('this', 'sky'), ('this', 'is'), ('this', 'blue'), ('is', 'sky'), ('is', 'is'), ('is', 'blue'),
('btechgeeks', 'sky'), ('btechgeeks', 'is'), ('btechgeeks', 'blue')]
Itertools.product() in Python
Python itertools.product: Below are the ways to implement Itertools. product() in Python.
Method #1: Using Itertools.product() (Static Input)
I)Number lists
Approach:
- Import product from itertools using the import keyword.
- Give the first list as static input and store it in a variable.
- Give the second list as static input and store it in another variable.
- We use the product function to create a list, which we then print.
- Print the Product of the two lists.
- The Exit of the Program.
Below is the implementation:
# Import product from itertools using the import keyword.
from itertools import product
# Give the first list as static input and store it in a variable.
lstt1 = [4, 19, 11, 5]
# Give the second list as static input and store it in another variable.
lstt2 = [10, 9, 8, 6, 5, 3]
# We use the product function to create a list, which we then print.
productlists = list(product(lstt1, lstt2))
# Print the Product of the two lists.
print('The Cartesian Product of the two lists : ')
print(productlists)
Output:
The Cartesian Product of the two lists : [(4, 10), (4, 9), (4, 8), (4, 6), (4, 5), (4, 3), (19, 10), (19, 9), (19, 8), (19, 6), (19, 5), (19, 3), (11, 10), (11, 9), (11, 8), (11, 6), (11, 5), (11, 3), (5, 10), (5, 9), (5, 8), (5, 6), (5, 5), (5, 3)]
II)String lists
Approach:
- Import product from itertools using the import keyword.
- Give the first list(string list) as static input and store it in a variable.
- Give the second list(string list) as static input and store it in another variable.
- We use the product function to create a list, which we then print.
- Print the Product of the two lists.
- The Exit of the Program.
Below is the implementation:
# Import product from itertools using the import keyword.
from itertools import product
# Give the first list(string list) as static input and store it in a variable.
lstt1 = ['hello', 'this', 'is', 'btechgeeks']
# Give the second list(string list) as static input and store it in another variable.
lstt2 = ['sky', 'is', 'blue']
# We use the product function to create a list, which we then print.
productlists = list(product(lstt1, lstt2))
# Print the Product of the two lists.
print('The Cartesian Product of the two lists : ')
print(productlists)
Output:
The Cartesian Product of the two lists :
[('hello', 'sky'), ('hello', 'is'), ('hello', 'blue'), ('this', 'sky'), ('this', 'is'), ('this', 'blue'), ('is', 'sky'), ('is', 'is'), ('is', 'blue'),
('btechgeeks', 'sky'), ('btechgeeks', 'is'), ('btechgeeks', 'blue')]
Method #2: Using Itertools.product() (User Input)
I)Number lists
Approach:
- Import product from itertools using the import keyword.
- Give the first list as user input using list(),map(),input(),and split() functions.
- Store it in a variable.
- Give the second list as user input using list(),map(),input(),and split() functions.
- Store it in a variable.
- We use the product function to create a list, which we then print.
- Print the Product of the two lists.
- The Exit of the Program.
Below is the implementation:
# Import product from itertools using the import keyword.
from itertools import product
# Give the first list as user input using list(),map(),input(),and split() functions.
# Store it in a variable.
lstt1 = list(map(int, input(
'Enter some random List Elements separated by spaces = ').split()))
# Give the second list as user input using list(),map(),input(),and split() functions.
# Store it in a variable.
lstt2 = list(map(int, input(
'Enter some random List Elements separated by spaces = ').split()))
# We use the product function to create a list, which we then print.
productlists = list(product(lstt1, lstt2))
# Print the Product of the two lists.
print('The Cartesian Product of the two lists : ')
print(productlists)
Output:
Enter some random List Elements separated by spaces = 6 8 7 2 9 Enter some random List Elements separated by spaces = 11 12 The Cartesian Product of the two lists : [(6, 11), (6, 12), (8, 11), (8, 12), (7, 11), (7, 12), (2, 11), (2, 12), (9, 11), (9, 12)]
II)String lists
Approach:
- Import product from itertools using the import keyword.
- Give the first list as user input using list(),input(),and split() functions.
- Store it in a variable.
- Give the second list as user input using list(),input(),and split() functions.
- Store it in a variable.
- We use the product function to create a list, which we then print.
- Print the Product of the two lists.
- The Exit of the Program.
Below is the implementation:
# Import product from itertools using the import keyword.
from itertools import product
# Give the first list as user input using list(),input(),and split() functions.
# Store it in a variable.
lstt1 = list(input(
'Enter some random List Elements separated by spaces = ').split())
# Give the second list as user input using list(),input(),and split() functions.
# Store it in a variable.
lstt2 = list(input(
'Enter some random List Elements separated by spaces = ').split())
# We use the product function to create a list, which we then print.
productlists = list(product(lstt1, lstt2))
# Print the Product of the two lists.
print('The Cartesian Product of the two lists : ')
print(productlists)
Output:
Enter some random List Elements separated by spaces = good morning this is btechgeeks
Enter some random List Elements separated by spaces = how are you
The Cartesian Product of the two lists :
[('good', 'how'), ('good', 'are'), ('good', 'you'), ('morning', 'how'), ('morning', 'are'), ('morning', 'you'), ('this', 'how'),
('this', 'are'), ('this', 'you'), ('is', 'how'), ('is', 'are'), ('is', 'you'), ('btechgeeks', 'how'), ('btechgeeks', 'are'),
('btechgeeks', 'you')]
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