How to fill a new list with values from another two lists

Question

I was looking for an answer on stack, but I couldn't find the right answer.

I've two lists:

keys = ['banana', 'orange']
values = [3, 5]

And I wanna make a new list looking such like that:

newlist = ['banana', 'banana', 'banana', 'orange',
    'orange', 'orange', 'orange', 'orange']

Answer 1

You could use zip to iterate over (value, key) pairs.

out = []
for e in zip(values, keys):
    out.extend(e[0] * [e[1]])

It's also possible without a for loop, using a nested list comprehensions:

[y for x in zip(values, keys) for y in x[0] * [x[1]]]