'How do I change all negative numbers to zero in python?

I have one list

    list1 = [-10,1,2,3,9,-1]

I want to change the negative number to zero so that it looks like

    list1 = [0,1,2,3,9,0]

how can I do it? Thanks!

python list

Solution 1:^[1]

You can use comprehensions:

list2 = [0 if i < 0 else i for i in list1]

list2 = [(i > 0) * i for i in list1]

Note that the second variant only works with Python 3 since True == 1 and False == 0. It should work with Python 2 but there is no guarantee.

Solution 2:^[2]

You can alternatively use the map function

map(lambda x: max(x,0),list1)

Solution 3:^[3]

Iterate through the list and if it's less that 0 change it

def do_the_thing(old_list):
    new_list = []
    for num in old_list:
        if num < 0:
             new_list.append(0)
        else:
            new_list.append(num)
    return new_list

Solution 4:^[4]

Another option is to is numpy like this:

list2 = numpy.array(list1)
list2 = list2 * (list2 >= 0)

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1
Solution 2	Thiru
Solution 3	sabbahillel
Solution 4	yoavsnake

'How do I change all negative numbers to zero in python?

Solution 1:[1]

Solution 2:[2]

Solution 3:[3]

Solution 4:[4]

Sources

Related Questions

Solution 1:^[1]

Solution 2:^[2]

Solution 3:^[3]

Solution 4:^[4]