Simplify Chained Comparison

In Python you can "chain" comparison operations which just means they are "and"ed together. In your case, it'd be like this:

if start <= x <= end:

Reference: https://docs.python.org/3/reference/expressions.html#comparisons

It can be rewritten as:

start <= x <= end:

Or:

r = range(start, end + 1) # (!) if integers
if x in r:
    ....