python 数据的清理行为实例详解

>>>try:
raiseKeyboardInterrupt
finally:
print('Goodbye, world!')
Goodbye, world!
Traceback(most recent call last):
File"<pyshell#71>", line 2,in<module>
raiseKeyboardInterrupt
KeyboardInterrupt

>>>def divide(x, y):
try:
 result = x / y
exceptZeroDivisionError:
print("division by zero!")
else:
print("result is", result)
finally:
print("executing finally clause")
>>> divide(2,1)
result is2.0
executing finally clause
>>> divide(2,0)
division by zero!
executing finally clause
>>> divide("2","1")
executing finally clause
Traceback(most recent call last):
File"<pyshell#91>", line 1,in<module>
  divide("2","1")
File"<pyshell#88>", line 3,in divide

>>>for line in open("myfile.txt"):
print(line, end="")
Traceback(most recent call last):
File"<pyshell#94>", line 1,in<module>
for line in open("myfile.txt"):
FileNotFoundError:[Errno2]No such file or directory:'myfile.txt'

>>>with open("myfile.txt")as f:
for line in f:
print(line, end="")
Traceback(most recent call last):
File"<pyshell#98>", line 1,in<module>
with open("myfile.txt")as f:
FileNotFoundError:[Errno2]No such file or directory:'myfile.txt'