python-错误和异常
1.常见的错误
NameError
SyntaxError
IOError
ZeroDivisionError:10/0
ValueError:a=int('12ab')
2.try--except异常处理
#!/usr/bin/env python
import random
num = random.randint(0,100)
while True:
try:
guess = int(raw_input("Enter a number:"))
except ValueError,e:
print "Enter 1~100"
continue
if guess > num:
print "guess Bigger",guess
elif guess <num:
print "guess smaller",guess
else:
print "guess Ok ,game over"
break
print "\n"
3.with_as语句
with open('1.txt') as f:
for line in f.readlines():
print line
4.raise语句
raise语句用于主动抛出异常
语法格式:raise [exception[,args]]
exception: 异常类
raise TypeError "type error"
assert语句:
5.标准异常和自定义异常
class FileError(IOError):
pass
raise FileError,"File Error"
try:
raise FileError,"File Error"
except FileError,e:
print e