Pascal's Triangle I

My Solution

Python

def generate(numRows: int) -> List[List[int]]:
    pascals_triangle = [[1]]

    if numRows > 1:
        pascals_triangle.append([1,1])

    for i in range(2, numRows):
        l = []
        l.append(1)
        prev_triangle = pascals_triangle[i-1]

        for j in range(len(prev_triangle) - 1):
            l.append(prev_triangle[j] + prev_triangle[j+1])

        l.append(1)
        pascals_triangle.append(l)

    return pascals_triangle