Python: Mapping from intervals to values

import bisect
bisect.bisect_left([100,300,500,800,1000], p)

here the docs: bisect


It is indeed quite horrible. Without a requirement to have no hardcoding, it should have been written like this:

if p <= 100:
    return 0
elif p <= 300:
    return 1
elif p <= 500:
    return 2
elif p <= 800:
    return 3
elif p <= 1000:
    return 4
else:
    return 5

Here are examples of creating a lookup function, both linear and using binary search, with the no-hardcodings requirement fulfilled, and a couple of sanity checks on the two tables:

def make_linear_lookup(keys, values):
    assert sorted(keys) == keys
    assert len(values) == len(keys) + 1
    def f(query):
        return values[sum(1 for key in keys if query > key)]
    return f

import bisect
def make_bisect_lookup(keys, values):
    assert sorted(keys) == keys
    assert len(values) == len(keys) + 1
    def f(query):
        return values[bisect.bisect_left(keys, query)]
    return f

You could try a take on this:

def check_mapping(p):
    mapping = [(100, 0), (300, 1), (500, 2)] # Add all your values and returns here

    for check, value in mapping:
        if p <= check:
            return value

print check_mapping(12)
print check_mapping(101)
print check_mapping(303)

produces:

0
1
2

As always in Python, there will be any better ways to do it.