1.获取移动平均值
def wrapper(fun):
def inner(*args,**kwargs):
ret=fun(*args,**kwargs)
ret.__next__()
return ret
return inner
@wrapper
def g():
sum=0
count=0
avg=0
while True:
num=yield avg
sum+=num
count+=1
avg=sum/count
f=g()
print(f.send(10))
print(f.send(20))
print(f.send(30))
2.处理文件:用户指定要查找的文件和内容 将文件中包含要查找内容的每一行都输出到屏幕
def search():
with open("a1.txt",encoding="utf-8") as f1:
for i in f1:
if "我" in i:
yield i
g=search()
for i in g:
print(i.strip())
3.写生成器,从文件中读取内容,在每一次读取到的内容之前加上‘***’之后再返回用户
def file_add():
with open("a1.txt",encoding="utf-8") as f1:
for i in f1:
yield "***"+i
g=file_add()
for i in g:
print(i.strip())
4.面试题
def demo():
for i in range(4):
yield i
g=demo()
g1=(i for i in g)
g2=(i for i in g1)
print(list(g1))
print(list(g2))
面试题1
def add(n,i):
return n+i
def test():
for i in range(4):
yield i
g=test()
for n in [1,10]:
g=(add(n,i) for i in g)
print(list(g))
import os
def init(func):
def wrapper(*args,**kwargs):
g=func(*args,**kwargs)
next(g)
return g
return wrapper
@init
def list_files(target):
while 1:
dir_to_search=yield
for top_dir,dir,files in os.walk(dir_to_search):
for file in files:
target.send(os.path.join(top_dir,file))
@init
def opener(target):
while 1:
file=yield
fn=open(file)
target.send((file,fn))
@init
def cat(target):
while 1:
file,fn=yield
for line in fn:
target.send((file,line))
@init
def grep(pattern,target):
while 1:
file,line=yield
if pattern in line:
target.send(file)
@init
def printer():
while 1:
file=yield
if file:
print(file)
g=list_files(opener(cat(grep('python',printer()))))
g.send('/test1')
协程应用:grep -rl /dir
tail&grep