The syntax a if b else c
is a ternary operator in Python that evaluates to a
if the condition b
is true – otherwise, it evaluates to c
. It can be used in comprehension statements:
>>> [a if a else 2 for a in [0,1,0,3]] [2, 1, 2, 3]
So for your example,
table = ''.join(chr(index) if index in ords_to_keep else replace_with for index in xrange(15))