Pascal

better_pascal.py

def better_pascal(n):
    def row(n):
        row = [1]
        for i in range(n):
            row.append(row[i] * (n - i) // (i + 1))
        return row

    return [row(i) for i in range(n)]

naive_pascal.py

def naive_pascal(n):
    def mul(ns):
        if not ns:
            return 1
        return ns[0] * mul(ns[1:])

    def C(n, k):
        return mul(range(n, n - k, -1)) // mul(range(1, k + 1))

    def row(n):
        return [C(n, i) for i in range(n + 1)]

    return [row(i) for i in range(n)]