varenummer = ['817', '817', '4011', '4048', '4045', '4045', '4045', '818', '9009', '9009', '9307']

antall_varer = {}

for vare in varenummer:
    if vare not in antall_varer:
        antall_varer[vare] = 1
    else:
        antall_varer[vare] += 1

print(antall_varer)