dic = dict.fromkeys([‘a‘, ‘b‘, ‘c‘],‘love‘)
print(dic)
输出：{‘a‘: ‘love‘, ‘b‘: ‘love‘, ‘c‘: ‘love‘}

v = dic.setdefault(‘k5‘, 333)
print(dic)
print(v)
输出：{"k1" : "aaa", "k2" : "bbb", "k3" : 111, "k4" : 222, "k5" : 333}
输出：333

dic = {"k1" : "aaa", "k2" : "bbb", "k3" : 111, "k4" : 222}
dic.update(k1 = 111, k3 = "aaa", k5 = "ccc")　　#也可以传入字典，如{‘k1‘:111, ‘k3‘:‘aaa‘, ‘k5‘:‘ccc‘}
print(dic)
输出：{"k1" : 111, "k2" : "bbb", "k3" : "aaa", "k4" : 222, "k5" : "ccc"}

del dic["k1"]
print(dic)
输出：{"k2" : "bbb", "k3" : 111, "k4" : 222}

dic.pop(‘k4‘)
print(dic)
输出：{"k1" : "aaa", "k2" : "bbb", "k3" : 111}

dic = {"k1" : "aaa", "k2" : "bbb", "k3" : 111, "k4" : 222}
k, v = dic.popitem()
print(dic)
print(k, v)
输出：{"k1" : "aaa", "k2" : "bbb", "k3" : 111}
输出：k4 222

for value in dic.values():
    print(value)
输出：aaa
     bbb
     111
     222

for value in dic.items():
    print(value)
输出：(‘k1‘ : ‘aaa‘)
     (‘k2‘ : ‘bbb‘)
     (‘k3‘ : 111)
     (‘k4‘ : 222)

for k, v in dic.items():
    print(k, v)
输出：k1 aaa
     k2 bbb
     k3 111
     k4 222

value = dic.get(‘k5‘, ‘没有这个key‘)
print(value)
输出：没有这个key