生成器表达式 和 列表推导式

[i** 2 for i in [1,2,3]]
print(li)

li2=[int(i/2) for i in range(0,7,2)]
print(li2)

# 生成器 表达式  简化代码

g=(i for i in range(5))     # 没有元组推导式
for i in g:
    print(i)

0  list=[{‘name‘:‘alex‘,‘age‘:80},{‘name‘:‘egon‘,‘age‘:40},{‘name‘:‘neza‘,‘age‘:18}]
   li=[(‘名字 %s‘%i[‘name‘],‘年龄 %d‘%i[‘age‘]) for i in list if i[‘age‘]>30]
   print(li)


#  [(‘名字 alex‘, ‘年龄 80‘), (‘名字 egon‘, ‘年龄 40‘)]

1  li=[i for i in range(31) if i%3==0]
   print(li)

2  li2=[i**2 for i in range(31) if i%3==0]
   print(li2)


3   names = [[‘Tom‘, ‘Billy‘, ‘Jefferson‘, ‘Andrew‘, ‘Wesley‘, ‘Steven‘, ‘Joe‘],
         [‘Alice‘, ‘Jill‘, ‘Ana‘, ‘Wendy‘, ‘Jennifer‘, ‘Sherry‘, ‘Eva‘]]

    li=[item for line in names for item in line if item.count(‘e‘)>=2]

    print(li)

          集合 字典 推导式

mydict={‘a‘:10,‘b‘:34,‘A‘:15,‘C‘:3,‘c‘:9}

nedic={k:mydict[k]**2 for k in mydict}
print(nedic)

#        求大小对应的键   的和
mydic={k.lower():(mydict.get(k.lower(),0)+mydict.get(k.upper(),0)) for k in mydict}

print(mydict)