Loop-help for a newbie?

[perfringo]

Result of this piece of code:

cols = list(zip(['B', 'D', 'F', 'H'], ['C', 'E', 'G', 'I'])) 

is same as this:

cols = [('B', 'C'), ('D', 'E'), ('F', 'G'), ('H', 'I')]

As second way requires less typing (and less conversion too) it may be better. However, zip is very handy if there are already existing lists. For example, if you have already lists for columns (say first and second) created in your code earlier then you can do:

cols = list(zip(first, second))