Regex help for newbie

[perfringo]

It seems to me that if you are looking for certain strings it will be easier without regex

I am not familiar with Python 2 syntax therefore I use Python 3 code:

with open('cars.txt', 'r') as source:
    cars = ['[cars]\n']
    trucks = ['[trucks]\n']
    for row in source:
        if 'car' in row:
            cars.append(row)
        elif 'truck' in row:
            trucks.append(row)

with open('cars_result.txt', 'w') as filtered:
    print(*cars, *trucks, file=filtered)

cars_result.txt will look like:

Output:
[cars]
 car1
 car2
 [trucks]
 truck1
 truck12
 truck13

Ansible is not my cup of tea but quick check of documentation revealed statements about support of Python 3.

In your code you use old-style open and 'with open(...'. What is the reason of such mix?