Perform List Subtraction in Python
In this article, we will learn to perform subtraction on a list in Python. We will use some built-in functions and some custom code as well. Let's first have a quick look over what is list and list subtraction in Python.
Python has a built-in data type called list. It is like a collection of arrays with different methodology. Data inside the list can be of any type say, integer, string or a float value, or even a list type. The list uses comma-separated values within square brackets to store data. Lists can be defined using any variable name and then assigning different values to the list in a square bracket. The list is ordered, changeable, and allows duplicate values.
list1 = ["Ram","Arun","Kiran"] list2 = [16,78,32,67] list3 = [‘apple’,’mango’,16,’cherry’,3.4]
List subtraction uses two lists and returns a new list after subtraction. This is similar to performing a subtraction operation in mathematics. It finds the difference between each element at each index from the given two lists.
#input list1 = [4,8,1,9,5] list2 = [1,4,2,6,7] #output list3 = [3,4,-1,3,-2] New List = Elements of List1 - Elements of List2
To perform list subtraction, the two input lists must be of the same length and it should contain elements of the same type i.e. both lists must contain only numerical values. The given example subtracts the elements at each index in one list from the other list.
Example: List Subtraction Using zip() and "-" operator
This method uses
zip(iterator1, iterator2) with the list1 as
iterator1 and list2 as
iterator2 to return a zip object. It uses a for-loop to iterate over the zip object and subtract the lists' elements from each other and store the result in a new list.
#takes two input lists list1 = [4, 8, 1, 9, 5] list2 = [1, 4, 2, 6, 7] #empty list sub_list =  #two lists are passed to zip zip_object = zip(list1, list2) #loop to find diff of each element for list1_i, list2_i in zip_object: sub_list.append(list1_i - list2_i) print(sub_list)
[3, 4, -1, 3, -2]
In this article, we learned to find the difference between each element of two lists by traversing them using a
zip object. We learned to perform list subtraction over each element.