initialise 2 dimensional array in python code example

Example 1: python initialize a 2d array

bar = [SOME EXPRESSION for item in some_iterable]

Example 2: 2d array python initialize

>>> b = [['a']*3]*3
>>> b
[['a', 'a', 'a'], ['a', 'a', 'a'], ['a', 'a', 'a']]
>>> b[1][1]
'a'
>>> b[1][1] = 'b'
>>> b
[['a', 'b', 'a'], ['a', 'b', 'a'], ['a', 'b', 'a']]