Python – Rear element extraction from list of tuples records
While working with tuples, we store different data as different tuple elements. Sometimes, there is a need to print specific information from the tuple like rear index. For instance, a piece of code would want just names to be printed of all the student data. Let’s discuss certain ways how one can achieve solutions to this problem.
Method #1 : Using list comprehension
List comprehension is the simplest way in which this problem can be solved. We can just iterate over only the rear index value in all the index and store it in a list and print it after that.
# Python3 code to demonstrate # Rear element extraction from Records # using list comprehension # initializing list of tuples test_list = [( 1 , 'Rash' , 21 ), ( 2 , 'Varsha' , 20 ), ( 3 , 'Kil' , 19 )] # printing original list print ( "The original list is : " + str (test_list)) # using list comprehension to get names # Rear element extraction from Records res = [lis[ - 1 ] for lis in test_list] # printing result print ( "List with only rear tuple element : " + str (res)) |
The original list is : [(1, 'Rash', 21), (2, 'Varsha', 20), (3, 'Kil', 19)] List with only rear tuple element : [21, 20, 19]
Method #2 : Using map() + itemgetter()
map()
coupled with itemgetter()
can perform this task in more simpler way. map() maps all the element we access using itemgetter()
and returns the result.
# Python3 code to demonstrate # Rear element extraction from Records # using map() + itergetter() from operator import itemgetter # initializing list of tuples test_list = [( 1 , 'Rash' , 21 ), ( 2 , 'Varsha' , 20 ), ( 3 , 'Kil' , 19 )] # printing original list print ( "The original list is : " + str (test_list)) # using map() + itergetter() to get names # Rear element extraction from Records res = list ( map (itemgetter( - 1 ), test_list)) # printing result print ( "List with only rear tuple element : " + str (res)) |
The original list is : [(1, 'Rash', 21), (2, 'Varsha', 20), (3, 'Kil', 19)] List with only rear tuple element : [21, 20, 19]