python list comprehension to produce two values in one iteration

Question

I want to generate a list in python as follows -

[1, 1, 2, 4, 3, 9, 4, 16, 5, 25 .....]

You would have figured out, it is nothing but n,

Answer 1

A little-known trick: list comprehensions can have multiple for clauses.

For example:

>>> [10*x+y for x in range(4) for y in range(3)]
[0, 1, 2, 10, 11, 12, 20, 21, 22, 30, 31, 32]

In your particular case, you could do:

>>> [x*x if y else x for x in range(5) for y in range(2)]
[0, 0, 1, 1, 2, 4, 3, 9, 4, 16]