异常捕获

def testTry(index,flag=False):
	stulst=["John","Jenny","Tom"]
	if flag:
		try:
			astu=stulst[index]
		except IndexError:
			print("IndexError")
		return 'Try Test Finished!'
	else:
		astu=stulst[index]
		return 'No try test Finished'
print('Right params testing start.........')
print(testTry(1,True))
print(testTry(1))
print("Error params testing start......")
print(testTry(4,True))
print(testTry(4))

运行结果：

Right params testing start.........
Traceback (most recent call last):
Try Test Finished!
No try test Finished
Error params testing start......
IndexError
Try Test Finished!
  File "E:\cla.py", line 17, in <module>
    print(testTry(4))
  File "E:\cla.py", line 10, in testTry
    astu=stulst[index]
IndexError: list index out of range
[Finished in 0.2s]

另一个例子：

def testTryFinally(index):  #此处函数内没有self参数，因为不是类中的函数
	stulst=['John','Jenny','Tom']
	af=open('my.txt','wt+')
	try:
		af.write(stulst(index))
	except:
		pass
	finally:   #无论是否出现异常，finally下的语句都会执行
		af.close()
		print("File already had been closed!")
print('NO indexError....')
testTryFinally(1)
print('INdexError.......')
testTryFinally(4)

运行结果：

NO indexError....
File already had been closed!
INdexError.......
File already had been closed!
[Finished in 0.8s]