python全栈开发-前方高能-生成器和生成器表达式

def func():
    print("111")
    return 222
ret = func()
print(ret)
结果
111
222

def func():
    print("111")
    yield 222
ret = func()
print(ret)
结果:
<generator object func at 0x00000276E516DF68>

def func():
    print("111")
    yield 222

gener = func()# 这个时候函数不会执?. ?是获取到?成器
ret = gener.__next__()# 这个时候函数才会执?. yield的作?和return?样. 也是返回数据
print(ret)
结果:
111
222

def func():
    print("111")
    yield 222
    print('333')
    yield 444

gener = func()
ret = gener.__next__()
print(ret)
ret2 = gener.__next__()
print(ret2)
ret3 = gener.__next__()
print(ret3)# 最后?个yield执?完毕. 再次__next__()程序报错, 也就是说. 和return?关了.

结果:
111
Traceback (most recent call last):
222
  File "D:/pycodes/第13天/day13.py", line 117, in <module>
333
    ret3 = gener.__next__() # 最后?个yield执?完毕. 再次__next__()程序报错, 也就是说. 和return?关了.
444
StopIteration

def cloth():
    lst = []
    for i in range(0,10000):
        lst.append('衣服'+str(i))
    return lst
cl = cloth()

def cloth():
    for i in range(0, 10000):
        yield "?服"+str(i)
cl = cloth()
print(cl.__next__())
print(cl.__next__())
print(cl.__next__())
print(cl.__next__())

def eat():
    print("我吃什么啊")
    a = yield "馒头"
    print("a=",a)
    b = yield "?饼"
    print("b=",b)
    c = yield "?菜盒?"
    print("c=",c)
    yield "GAME OVER"
gen = eat() # 获取?成器
ret1 = gen.__next__()
print(ret1)
ret2 = gen.send("胡辣汤")
print(ret2)
ret3 = gen.send("狗粮")
print(ret3)
ret4 = gen.send("猫粮")
print(ret4)

def func():
    print(111)
    yield 222
    print(333)
    yield 444
    print(555)
    yield 666
gen = func()
for i in gen:
    print(i)
结果:
111
222
333
444
555
666

lst = []
for i in range(1, 15):
    lst.append(i)
print(lst)

lst = [i for i in range(1, 15)]
print(lst)

lst = ['python%s' % i for i in range(1,15)]
print(lst)

# 获取1-100内所有的偶数
lst = [i for i in range(1, 100) if i % 2 == 0]
print(lst)

gen = (i for i in range(10))
print(gen)
结果:
<generator object <genexpr> at 0x106768f10>

gen = ("麻花藤我第%s次爱你" % i for i in range(10))
for i in gen:
     print(i)

# 1.获取1-100内能被3整除的数
lst = [i for i in range(1,101) if i%3==0]
print(lst)
# 2.100以内能被3整除的数的平?
lst = [i*i for i in range(1,101) if i%3==0]
print(lst)
# 3.寻找名字中带有两个e的?的名字
names = [['Tom', 'Billy', 'Jefferson' , 'Andrew' , 'Wesley' , 'Steven' ,'Joe'],['Alice', 'Jill' , 'Ana', 'Wendy', 'Jennifer', 'Sherry' , 'Eva']]
lst = [a for i in names for a in i if a.count('e')==2]
print(lst)

def func():
    print(111)
    yield 222
g = func() # ?成器g
g1 = (i for i in g) # ?成器g1. 但是g1的数据来源于g
g2 = (i for i in g1) # ?成器g2. 来源g1
print(list(g)) # 获取g中的数据. 这时func()才会被执?. 打印111.获取到222. g完毕.
print(list(g1)) # 获取g1中的数据. g1的数据来源是g. 但是g已经取完了. g1 也就没有数据了
print(list(g2)) # 和g1同理

# 把字典中的key和value互换
dic = {'a': 1, 'b': '2'}
new_dic = {dic[key]: key for key in dic}
print(new_dic)
# 在以下list中. 从lst1中获取的数据和lst2中相对应的位置的数据组成?个新字典
lst1 = ['jay', 'jj', 'sylar']
lst2 = ['周杰伦', '林俊杰', '邱彦涛']
dic = {lst1[i]: lst2[i] for i in range(len(lst1))}
print(dic)

lst = [1, -1, 8, -8, 12]
# 绝对值去重
s = {abs(i) for i in lst}
print(s)