python如何遍历dict

for key in a:

     pritn(key+':'+a[key])

for key in a.keys():

      print(key+':'+a[key])

for value in a.values():

    print(value)

for kv in a.items():

    print(kv)

（‘a’,'1'）(...)

for key,value in a.items():

    print(key+':'+value)

for (key,value) in a.items():

    print(key+':'+value)