吴裕雄--天生自然 PYTHON3开发学习：字典

dict = {'Alice': '', 'Beth': '', 'Cecil': ''}

dict1 = { 'abc': 456 }
dict2 = { 'abc': 123, 98.6: 37 }

dict = {'Name': 'Runoob', 'Age': 7, 'Class': 'First'}
 
print ("dict['Name']: ", dict['Name'])
print ("dict['Age']: ", dict['Age'])

dict = {'Name': 'Runoob', 'Age': 7, 'Class': 'First'}
 
print ("dict['Alice']: ", dict['Alice'])

dict = {'Name': 'Runoob', 'Age': 7, 'Class': 'First'}
 
dict['Age'] = 8               # 更新 Age
dict['School'] = "菜鸟教程"  # 添加信息
 
print ("dict['Age']: ", dict['Age'])
print ("dict['School']: ", dict['School'])

dict = {'Name': 'Runoob', 'Age': 7, 'Class': 'First'}
 
del dict['Name'] # 删除键 'Name'
dict.clear()     # 清空字典
del dict         # 删除字典
 
print ("dict['Age']: ", dict['Age'])
print ("dict['School']: ", dict['School'])

dict = {'Name': 'Runoob', 'Age': 7, 'Name': '小菜鸟'}
 
print ("dict['Name']: ", dict['Name'])

dict = {['Name']: 'Runoob', 'Age': 7}
 
print ("dict['Name']: ", dict['Name'])

dict = {'Name': 'Zara', 'Age': 7}
 
print ("字典长度 : %d" %  len(dict))
dict.clear()
print ("字典删除后长度 : %d" %  len(dict))

dict1 = {'Name': 'Runoob', 'Age': 7, 'Class': 'First'}
 
dict2 = dict1.copy()
print ("新复制的字典为 : ",dict2)

dict1 =  {'user':'runoob','num':[1,2,3]}
 
dict2 = dict1          # 浅拷贝: 引用对象
dict3 = dict1.copy()   # 浅拷贝：深拷贝父对象（一级目录），子对象（二级目录）不拷贝，还是引用
 
# 修改 data 数据
dict1['user']='root'
dict1['num'].remove(1)
 
# 输出结果
print(dict1)
print(dict2)
print(dict3)

seq = ('name', 'age', 'sex')
 
dict = dict.fromkeys(seq)
print ("新的字典为 : %s" %  str(dict))
 
dict = dict.fromkeys(seq, 10)
print ("新的字典为 : %s" %  str(dict))

x = ('key1', 'key2', 'key3')
 
thisdict = dict.fromkeys(x)
 
print(thisdict)

dict = {'Name': 'Runoob', 'Age': 27}
 
print ("Age 值为 : %s" %  dict.get('Age'))
print ("Sex 值为 : %s" %  dict.get('Sex', "NA"))

dict = {'Name': 'Runoob', 'Age': 7}
 
# 检测键 Age 是否存在
if  'Age' in dict:
    print("键 Age 存在")
else :
    print("键 Age 不存在")
 
# 检测键 Sex 是否存在
if  'Sex' in dict:
    print("键 Sex 存在")
else :
    print("键 Sex 不存在")
 
# not in
 
# 检测键 Age 是否存在
if  'Age' not in dict:
    print("键 Age 不存在")
else :
    print("键 Age 存在")

dict = {'Name': 'Runoob', 'Age': 7}
 
print ("Value : %s" %  dict.items())

dict = {'Name': 'Runoob', 'Age': 7}
 
print ("Age 键的值为 : %s" %  dict.setdefault('Age', None))
print ("Sex 键的值为 : %s" %  dict.setdefault('Sex', None))
print ("新字典为：", dict)

dict = {'Name': 'Runoob', 'Age': 7}
dict2 = {'Sex': 'female' }
 
dict.update(dict2)
print ("更新字典 dict : ", dict)

dict = {'Sex': 'female', 'Age': 7, 'Name': 'Zara'}
 
print ("字典所有值为 : ",  list(dict.values()))

site= {'name': '菜鸟教程', 'alexa': 10000, 'url': 'www.runoob.com'}
pop_obj=site.popitem()
print(pop_obj)
print(site)