【python爬虫】- json，dict

importjson

dict_a={}

dict_b=dict()

# dict_a['a1']='b1'

# dict_a['a2']='b2'

# dict_a['a3']='b3'

dict_a={'a1':'b1','a2':'b2','a3':'b3'}

print(dict_a)

ks=dict_a.keys()

print(ks,type(ks))

vs=dict_a.values()

print(vs,type(vs))

print(dict_a.items())

# dd=dict_a["a1"]

# dict_a['a1']=dict_a['a3']

# dict_a['a3']=dd

dict_a['a1']='b3'

dict_a['a3']='b1'

print(dict_a)

dict_a.pop('a1')

print(dict_a)

dict_b.update(dict_a)

print(dict_b)

a1=dict_b.get('a1')

print(a1)

dict_b['a1']=a1

print(dict_b)

a4=dict_b.get('a4','null')

dict_b['a4']=a4

print(dict_b,type(dict_b))

json_c=json.dumps(dict_b)

print(json_c,type(json_c))

dict_c=json.loads(json_c)

print(dict_c,type(dict_c))

以下为输出结果：

{'a1': 'b1', 'a2': 'b2', 'a3': 'b3'}dict_keys(['a1', 'a2', 'a3'])dict_values(['b1', 'b2', 'b3'])dict_items([('a1', 'b1'), ('a2', 'b2'), ('a3', 'b3')]){'a1': 'b3', 'a2': 'b2', 'a3': 'b1'}{'a2': 'b2', 'a3': 'b1'}{'a2': 'b2', 'a3': 'b1'}None{'a2': 'b2', 'a3': 'b1', 'a1': None}{'a2': 'b2', 'a3': 'b1', 'a1': None, 'a4': 'null'}{"a2": "b2", "a3": "b1", "a1": null, "a4": "null"}{'a2': 'b2', 'a3': 'b1', 'a1': None, 'a4': 'null'}