else 与with 语句
1.else 语句2.with 语句
1.else 语句
while - else 语句
list1
=[x
for x
in range(0,100)]
i
,s
=0,0
while i
<100 :
s
=list1
[i
]+s
i
+=1
else:
print('100以内的整数和是%d'%s
)
for - else 语句
s
=0
for i
in range(0,100):
s
+=i
else:
print('100以内的整数和是%d'%s
)
try -except - else 语句
import random
try:
n
=[random
.randint
(0,100)]
m
=[random
.randint
(0,100)]
x
=m
[0]/n
[0]
except ZeroDivisionError
as z
:
print('n是零')
else:
print(x
)
2.with 语句
with是一种上下文管理协议，常用于文件处理，可以简化try….except….finlally的处理流程。（文件打开后必须关闭，处理异常时往往需要finally 语句以关闭文件，而with 语句可以省略这一步）
with expression
[as target
]:
代码过程
try:
with open('a.txt','w') as f
:
for lines
in f
:
print(lines
)
except OSError
as o
:
print(o
)
