Question: 
Write a function to locate the left insertion point for a specified value in sorted order.


Model's Code:
def left_insertion(arr, value):
    left, right = 0, len(arr)
    while left < right:
        mid = (left + right) // 2
        if arr[mid] < value:
            left = mid + 1
        else:
            right = mid
    return left



Sample Correct Code:
import bisect
def left_insertion(a, x):
    i = bisect.bisect_left(a, x)
    return i


Asserts:
assert left_insertion([1,2,4,5],6)==4
assert left_insertion([1,2,4,5],3)==2
assert left_insertion([1,2,4,5],7)==4


Tests:
Test 1 of 3: PASS
Test 2 of 3: PASS
Test 3 of 3: PASS

Test 736 of 974: 558/736 (75.81521739130434%): success