Python – Remove Negative Elements in List
Sometimes, while working with Python lists, we can have a problem in which we need to remove all the negative elements from list. This kind of problem can have application in many domains such as school programming and web development. Let’s discuss certain ways in which this task can be performed.
Input : test_list = [6, 4, 3]
Output : [6, 4, 3]Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.
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Input : test_list = [-6, -4]
Output : []
Method #1 : Using list comprehension
The combination of above functions can be used to solve this problem. In this, we perform the task of removing negative elements by iteration in one liner using list comprehension
# Python3 code to demonstrate working of # Remove Negative Elements in List# Using list comprehension # initializing listtest_list = [5, 6, -3, -8, 9, 11, -12, 2] # printing original listprint("The original list is : " + str(test_list)) # Remove Negative Elements in List# Using list comprehensionres = [ele for ele in test_list if ele > 0] # printing result print("List after filtering : " + str(res)) |
The original list is : [5, 6, -3, -8, 9, 11, -12, 2] List after filtering : [5, 6, 9, 11, 2]
Method #2 : Using filter() + lambda
The combination of above functions can also offer an alternative to this problem. In this, we extend logic of retaining positive formed using lambda function and extended using filter().
# Python3 code to demonstrate working of # Remove Negative Elements in List# Using filter() + lambda # initializing listtest_list = [5, 6, -3, -8, 9, 11, -12, 2] # printing original listprint("The original list is : " + str(test_list)) # Remove Negative Elements in List# Using filter() + lambdares = list(filter(lambda x : x > 0, test_list)) # printing result print("List after filtering : " + str(res)) |
The original list is : [5, 6, -3, -8, 9, 11, -12, 2] List after filtering : [5, 6, 9, 11, 2]
