Python offers you different types of comprehensions:
We'll concentrate on the first one for now, and then it will be easy to explain the other two.
list comprehension is a quick way of making a list. Usually the list is the result of some operation that may involve applying a function, filtering, or building a different data structure.
Let's start with a very simple example I want to calculate a list with the squares of the first 10 natural numbers. How would you do it? There are a couple of equivalent ways:
# If you code like this you are not a Python guy! ;) >>> squares =  >>> for n in range(10): ... squares.append(n ** 2) ... >>> list(squares) [0, 1, 4, 9, 16, 25, 36, 49, 64, 81] # This is ...