python中怎麽用兩個列表組合成字典,相同key的vlue值組成列表

listb=['1','2','3','4','5','6','7']

dict={}

for?i,j?in?zip(lista,listb):

if?i?not?in?dict.keys():

dict[i]=j

else:

dict[i]=[dict[i]]

dict[i].append(j)

print(dict)