List Comprehensions in Python

list_comprehensions.py

# Why list comprehensions?

fruits = ['orange', 'apple', 'pineapple']
things = ['potato', 'orange', 'car', 'apple']

# This will filter things and will create a new list with only fruits from
# things
new_list_of_things = []
for thing in things:
    if thing in fruits:
        new_list_of_things.append(thing)

# >>> print (new_list_of_things)
# >>> ['orange', 'apple']


# We can re-do that in a more clear way in list comprehensions

# This will just give us a copy of the original list
new_list_of_things = [thing for thing in things]
# >>> print (new_list_of_things)
# >>> ['potato', 'orange', 'car', 'apple']

# ...but we can also do conditions inside the list comprehension:
new_list_of_things = [thing for thing in things if thing in fruits]
# >>> print (new_list_of_things)
# >>> ['orange', 'apple']

# This is exactly what we did above, in just one line and without creating an
# empty list beforehand