Help: List comprehension

[mart79]

I have the following piece of code which I want to simplify/write more clean using list comprehension.
How would I achieve this?

        type_list = []

        input = [['car', 'red', '10'], ['train', 'blue', '20'], ['airplane', 'gray', '300']]
        if input is not None:
            for entry in input:
                if entry[0] != 'car':
                    type_list.append(entry[0])
                else:
                    type_list.append(None)

        return type_list

[buran]

foo = [['car', 'red', '10'], ['train', 'blue', '20'], ['airplane', 'gray', '300']]

# list comprehension
bar = [first if first != 'car' else None for first, *rest in foo]
print(bar)

# using a function
def check(first, *rest):
    if first != 'car':
        return first
bar = [check(*item) for item in foo]
print(bar)

# or simplifying your code
bar = []
for first, *rest in foo:
    bar.append(first if first != 'car' else None)
print(bar)

Note that list comprehension doesn't always improve the code.
also, don't use input as name, you are overriding the built-in function input()

[mart79]

foo = [['car', 'red', '10'], ['train', 'blue', '20'], ['airplane', 'gray', '300']]

# list comprehension
bar = [first if first != 'car' else None for first, *rest in foo]
print(bar)

# using a function
def check(first, *rest):
    if first != 'car':
        return first
bar = [check(*item) for item in foo]
print(bar)

# or simplifying your code
bar = []
for first, *rest in foo:
    bar.append(first if first != 'car' else None)
print(bar)

Note that list comprehension doesn't always improve the code.
also, don't use input as name, you are overriding the built-in function input()

Thank you very much for your swift reply! I understand not using input.

[ndc85430]

Why do you need the if statement on line 4? Clearly the expression input is not None isn't going to be False.

[mart79]

Why do you need the if statement on line 4? Clearly the expression input is not None isn't going to be False.

Because my input at some point can also be None, although that is not shown in the example I gave.