Python: efficiently check if integer is within *many* ranges

You can throw your ranges into tuples and put the tuples in a list. Then use any() to help you find if your value is within these ranges.

ranges = [(1000,2429), (2545,2575), (2640,2686), (2890, 2890)]
if any(lower <= postcode <= upper for (lower, upper) in ranges):
    print('M')