from functools import  reduce
name = ['joe','susan','black','lilia']
age = [19,20,18,30]
sex = ['m','w','w','m']
#案例一:格式化用户的英文名,要求首字母大小,其它字母小写
new_name = map(lambda x:x.title(),name)
print(list(new_name))
#案例二:将用户英文名、年龄、性别三个集合的数据结合到一起,形成一个元祖列表
users = map(lambda x,y,z:(x,y,z),name,age,sex)
new_users = list(users)
print(new_users)
#案例三:过滤性别为男的用户
m_users = filter(lambda x:x[2] =='m',new_users)
new_m_user = list(m_users)
print(new_m_user)
#案例四:求性别为男的用户的平均年龄
sum_age = reduce(lambda x,y:x+y[1],new_m_user,0)
print(sum_age/len(new_m_user))