1、定义
异常即是一个事件，该事件会在程序执行过程中发生，影响了程序的正常执行。
2、异常处理
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| """ 异常处理 """
from tool import topic
def demo_1():
print(x)
pass
def demo_2():
try:
print(5 / 0)
except (NameError, IOError):
print("There is a NameError or IOError occured.")
pass
def demo_3():
try:
print(x)
except:
print("Name Error occured.")
return
finally:
print("demo_3 end.")
print("In function demo_3.")
pass
if __name__ == "__main__":
demo_1()
demo_2()
demo_3()
pass
|
3、打印异常信息
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| """ 打印异常信息 """
import traceback
def demo_1():
try:
print(5 / 0)
except Exception as e:
print(e)
pass
def demo_2():
try:
print(5 / 0)
except Exception as e:
traceback.print_exc()
pass
if __name__ == "__main__":
demo_1()
demo_2()
pass
|
4、触发异常
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| """ 触发异常 """
from tool import topic
import traceback
@topic("Demo-1")
def demo_1():
try:
raise NameError
except Exception as e:
traceback.print_exc()
pass
@topic("Demo-2")
def demo_2():
level = 1
try:
if level == 1:
raise Exception("Invalid level!", level)
except Exception as e:
traceback.print_exc()
pass
if __name__ == "__main__":
demo_1()
demo_2()
pass
|
5、自定义异常
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| """ 自定义异常 """
class MyException(Exception):
def __init__(self, name, reason):
self.name = name
self.reason = reason
def demo_1():
try:
raise MyException("TimeoutError", "Connection timeout.")
except MyException as e:
print(f"{e.name}: {e.reason}")
pass
if __name__ == "__main__":
demo_1()
pass
|