Check If List Is Part Of List Keeping Order And Find Postion

I need to seek the 'matchingpoint' of two list where List 'a' is bigger than List 'b'. So far I've found this earlier post: Check if a list is part of another list while preserving

Solution 1:

You could use next to fetch the first matching point:

a = [3, 4, 1, 2, 4, 1, 5]
b = [4, 1, 2]

starting_point = next((a[i] for i in range(len(a)) if b == a[i:i + len(b)]), -1)

print(starting_point)

Output

4

UPDATE

If you need both the index and the value at the index, return the index instead of the value, for example:

position = next((i for i in range(len(a)) if b == a[i:i + len(b)]), -1)

print("position", position)
print("starting point", a[position])

Output

position 1
starting point 4

Note the change, now is i instead of a[i]