You want to create an array-like data structure in python. You know, how many entries you will need for your list. What do you do?
I always thought you have to do something like
lst =  for i in range(N): lst.append(None)
Today i learned here, that in python you can simply say
lst = [None]*N
and it is even much faster. I never stop learning, even after several years of using python 🙂