Some_function()在执行时引发异常,因此程序跳转到异常:
try:
some_function()
except:
print("exception happened!")
如何查看导致异常发生的原因?
Some_function()在执行时引发异常,因此程序跳转到异常:
try:
some_function()
except:
print("exception happened!")
如何查看导致异常发生的原因?
当前回答
实际的异常可以通过以下方式捕获:
try:
i = 1/0
except Exception as e:
print e
您可以从Python教程中了解有关异常的更多信息。
其他回答
使用下面的异常类型和异常文本
import sys
print(str(sys.exc_info()[0]).split(' ')[1].strip('>').strip("'")+"-"+(str(sys.exc_info()[1])))
如果你只想要异常类型:使用——>
import sys
print(str(sys.exc_info()[0]).split(' ')[1].strip('>').strip("'"))
由于Rajeshwar
为了补充Lauritz的答案,我创建了一个用于异常处理的装饰器/包装器,并且包装器记录发生了哪种类型的异常。
class general_function_handler(object):
def __init__(self, func):
self.func = func
def __get__(self, obj, type=None):
return self.__class__(self.func.__get__(obj, type))
def __call__(self, *args, **kwargs):
try:
retval = self.func(*args, **kwargs)
except Exception, e :
logging.warning('Exception in %s' % self.func)
template = "An exception of type {0} occured. Arguments:\n{1!r}"
message = template.format(type(e).__name__, e.args)
logging.exception(message)
sys.exit(1) # exit on all exceptions for now
return retval
这可以在类方法或带有装饰器的独立函数上调用:
@general_function_handler
完整的例子请参阅我的博客:http://ryaneirwin.wordpress.com/2014/05/31/python-decorators-and-exception-handling/
获取异常对象所属类的名称:
e.__class__.__name__
使用print_exc()函数也将打印堆栈跟踪,这是任何错误消息的基本信息。
是这样的:
from traceback import print_exc
class CustomException(Exception): pass
try:
raise CustomException("hi")
except Exception as e:
print ('type is:', e.__class__.__name__)
print_exc()
# print("exception happened!")
你会得到这样的输出:
type is: CustomException
Traceback (most recent call last):
File "exc.py", line 7, in <module>
raise CustomException("hi")
CustomException: hi
在打印和分析之后,代码可以决定不处理异常,只执行raise:
from traceback import print_exc
class CustomException(Exception): pass
def calculate():
raise CustomException("hi")
try:
calculate()
except CustomException as e:
# here do some extra steps in case of CustomException
print('custom logic doing cleanup and more')
# then re raise same exception
raise
输出:
custom logic doing cleanup and more
和解释器打印异常:
Traceback (most recent call last):
File "test.py", line 9, in <module>
calculate()
File "test.py", line 6, in calculate
raise CustomException("hi")
__main__.CustomException: hi
引发后,原始异常继续向上传播调用堆栈。(注意可能的陷阱)如果你引发新的异常,它会携带新的(更短的)堆栈跟踪。
from traceback import print_exc
class CustomException(Exception):
def __init__(self, ok):
self.ok = ok
def calculate():
raise CustomException(False)
try:
calculate()
except CustomException as e:
if not e.ok:
# Always use `raise` to rethrow exception
# following is usually mistake, but here we want to stress this point
raise CustomException(e.ok)
print("handling exception")
输出:
Traceback (most recent call last):
File "test.py", line 13, in <module>
raise CustomException(e.message)
__main__.CustomException: hi
注意traceback如何不包括第9行中的compute()函数,这是原始异常e的起源。
实际的异常可以通过以下方式捕获:
try:
i = 1/0
except Exception as e:
print e
您可以从Python教程中了解有关异常的更多信息。
使用类型class和as语句
try:#code
except Exception as e:
m=type(e)
#m is the class of the exception
strm=str(m)
#strm is the string of m