matriseEn = [[1,4,7],[2,5,8],[3,6,9]]

def bytt(matrise):
    ny_matrise = []
    for i in range(len(matrise)): # rader
        ny_matrise.append([])
        for j in range(len(matrise[i])): # kolonner i hver rad
            ny_matrise[i].append(matrise[j][i])

    return ny_matrise

print(bytt(matriseEn))