performance – Lo Shu Magic Square (Python)

I wrote a python program to find if a matrix is a magic square or not. It works, but I can’t help feeling like I may have overcomplicated the solution. I have seen other implementations that were a lot shorter, but I was wondering how efficient/inefficient my code is and how I could improve it and/or shorten it to achieve the result I am looking for.

def main():

    matrix = ((4,9,2),
    result = loShu(matrix)


def loShu(matrix):

    i = 0
    j = 0

    for i in range(0, len(matrix)):
        for j in range(0, len(matrix(j))):
            if ((matrix(i)(j) < 1) or (matrix(i)(j) > 9)):
                return ("This is not a Lo Shu Magic Square - one of the numbers is invalid")

    row1 = matrix(0)(0) + matrix(0)(1) + matrix(0)(2)
    row2 = matrix(1)(0) + matrix(1)(1) + matrix(1)(2)
    row3 = matrix(2)(0) + matrix(2)(1) + matrix(2)(2)

    ver1 = matrix(0)(0) + matrix(1)(0) + matrix(2)(0)
    ver2 = matrix(0)(1) + matrix(1)(1) + matrix(2)(1)
    ver3 = matrix(0)(2) + matrix(1)(2) + matrix(2)(2)

    diag1 = matrix(0)(0) + matrix(1)(1) + matrix(2)(2)
    diag2 = matrix(0)(2) + matrix(1)(1) + matrix(2)(0)

    checkList = (row1,row2,row3,ver1,ver2,ver3,diag1,diag2)

    temp = checkList(0)

    for x in range (0, len(checkList)):
        if checkList(x) != temp:
            return ("This is not a Lo Shu Magic Square")

    return ("This is a Lo Shu Magic Square")