3.字典的增删改查

# 字典
# 增
dic1 = {‘name‘:‘yasuo‘,‘age‘:‘20‘,‘weight‘:‘56‘,‘high‘:‘178‘}   
dic1[‘age‘] = 18
print(dic1)
dic1[‘like‘] = ‘wind‘ # 没有就添加，有就覆盖
print(dic1)

dic1.setdefault(‘weight‘,60) # 有就不改变，没有就添加

# 删
dic1.pop(‘high‘)  # 有返回值，按键去删除
print(dic1.pop(‘high1‘,‘没有这个键‘))  # 返回值可以设置
print(dic1)

print(dic1.popitem())  # 随机删除，有返回值，元组里面是删除的健值
print(dic1)

del dic1[‘high‘]
print(dic1)

dic1.clear() # 清空字典

# 改
dic1[‘age‘] = 18
print(dic1)

dic2 = {‘name‘:‘yasuo‘,‘weight‘:‘60‘}
dic2.update(dic1)
print(dic1)  #把dic1更新到dic2中，没有的就添加，有的不一样就覆盖

# 查
print(dic1.keys())
print(dic1.values())
print(dic1.items())

for i in dic1:
    print(i)  #循环打印键

for k,v in dic1.items():#items要记得
    print(k,v)

v1 = dic1[‘name‘]
print(v1)

v2 =dict[‘name1‘] # 没有就报错
print(v2)

print(dic1.get(‘name‘))
print(dic1.get(‘name1‘))
print(dic1.get(‘name1‘,‘没有这个键‘))  # 不会报错