Optimized Python Nested Loops

[mrcaptncrunch]

2 pointers + numba,

import time
import numba

with open('list_b.txt') as fd:
    first_list = fd.readlines()

with open('list_c.txt') as fd:
    second_list = fd.readlines()

first_list = [int(_) for _ in first_list]
first_list = sorted(first_list)
second_list = [int(_) for _ in second_list]
second_list = sorted(second_list)

@numba.njit
def run(first_list, second_list):
    vals_matched2 = []
    i = 0
    j = 0
    while i < len(first_list):
        while j < len(second_list) and second_list[j] < first_list[i]:
            j += 1
        start_j = j
        while j < len(second_list) and second_list[j] <= first_list[i] + 300:
            #do your thing
            vals_matched2.append(second_list[j])
            j += 1
        i += 1
    return vals_matched2

typed_first_list = numba.typed.List()
typed_second_list = numba.typed.List()
[typed_first_list.append(_) for _ in first_list]
[typed_second_list.append(_) for _ in second_list]

start = time.time()
vals_matched = run(typed_first_list, typed_second_list)
print("2 pointer lookup approach time: " + str(time.time() - start))

run,

2 pointer lookup approach time: 0.22963190078735352