How do you filter in Python using a function?

Question

I am using the filter function for the first time and using a function to remove del_num from a tuple called num_list. However, it's not doing what I want. I am getting back the original num_list values. Appreciate any ideas on how to get this to work.

num_list = [1,2,3,4,5,8,24,24,54,78]
del_num = 24

def filter_list(num_list, del_num):
    new_num =[]
    for v in num_list:
        if (num_list) == (del_num):
            return FALSE
        else:
            new_num.append(v)
    return new_num

result = filter_list(num_list,del_num)
print(result)

Answer 1

One way to do this is using list comprehension

num_list = [1,2,3,4,5,8,24,24,54,78]
del_num = 24

def filter_list(num_list,del_num):
    return [num for num in num_list if num != del_num]

filtered_list = filter_list(num_list,del_num)
print(filtered_list)

Answer 2

Making minimal changes to the overall structure of your code, but making some changes so it works:

num_list = [1,2,3,4,5,8,24,24,54,78]
del_num = 24

def filter_list(num_list, del_num):
    new_num = []
    for v in num_list:
        if v != del_num:
            new_num.append(v)
    return new_num

result = filter_list(num_list,del_num)
print(result)

The return False portion of your code will break out of the function and return False if the condition is met, which is not what you want. Additionally, the equality check you were doing was comparing the original list to the number to be deleted. You should have done if v == del_num . Given that all the action happens in the else block, easiest to turn the equality into an inequality and get rid of the else block entirely.

Also note that the boolean False is spelt False , not FALSE (unlike some other languages).

Answer 3

Here is what are you looking for:

num_list = [1,2,3,4,5,8,24,24,54,78]
del_num = 24

def filter_list(num_list, del_num):

 new_num =[]

for v in num_list:
    if (v) == (del_num):
        pass
    else:
        new_num.append(v)
return new_num

result = filter_list(num_list,del_num)

print(result)