我想在不退出的情况下捕获和记录异常,例如,
try:
do_stuff()
except Exception as err:
print(Exception, err)
# I want to print the entire traceback here,
# not just the exception name and details
我想打印与抛出异常时打印的完全相同的输出,而不使用try/,只是拦截异常,并且我不希望它退出程序。
我想在不退出的情况下捕获和记录异常,例如,
try:
do_stuff()
except Exception as err:
print(Exception, err)
# I want to print the entire traceback here,
# not just the exception name and details
我想打印与抛出异常时打印的完全相同的输出,而不使用try/,只是拦截异常,并且我不希望它退出程序。
当前回答
你可以这样做:
try:
do_stuff()
except Exception, err:
print(Exception, err)
raise err
其他回答
您需要将try/except放在可能发生错误的最内层循环中,即。
for i in something:
for j in somethingelse:
for k in whatever:
try:
something_complex(i, j, k)
except Exception, e:
print e
try:
something_less_complex(i, j)
except Exception, e:
print e
... 等等
换句话说,您需要将可能在try/中失败的语句包装在尽可能具体的内部循环中。
您需要traceback模块。它将允许您像Python通常那样打印堆栈转储。特别是,print_last函数将打印最后一个异常和堆栈跟踪。
import io
import traceback
try:
call_code_that_fails()
except:
errors = io.StringIO()
traceback.print_exc(file=errors) # Instead of printing directly to stdout, the result can be further processed
contents = str(errors.getvalue())
print(contents)
errors.close()
其他一些答案已经指出了回溯模块。
请注意,使用print_exc,在某些极端情况下,您将无法获得您所期望的结果。在Python 2.x中:
import traceback
try:
raise TypeError("Oups!")
except Exception, err:
try:
raise TypeError("Again !?!")
except:
pass
traceback.print_exc()
...将显示上一个异常的回溯:
Traceback (most recent call last):
File "e.py", line 7, in <module>
raise TypeError("Again !?!")
TypeError: Again !?!
如果你真的需要访问原始的回溯,一个解决方案是将exc_info返回的异常信息缓存到一个局部变量中,并使用print_exception显示它:
import traceback
import sys
try:
raise TypeError("Oups!")
except Exception, err:
try:
exc_info = sys.exc_info()
# do you usefull stuff here
# (potentially raising an exception)
try:
raise TypeError("Again !?!")
except:
pass
# end of useful stuff
finally:
# Display the *original* exception
traceback.print_exception(*exc_info)
del exc_info
生产:
Traceback (most recent call last):
File "t.py", line 6, in <module>
raise TypeError("Oups!")
TypeError: Oups!
但这也有一些陷阱:
From the doc of sys_info: Assigning the traceback return value to a local variable in a function that is handling an exception will cause a circular reference. This will prevent anything referenced by a local variable in the same function or by the traceback from being garbage collected. [...] If you do need the traceback, make sure to delete it after use (best done with a try ... finally statement) but, from the same doc: Beginning with Python 2.2, such cycles are automatically reclaimed when garbage collection is enabled and they become unreachable, but it remains more efficient to avoid creating cycles.
另一方面,通过允许你访问与异常相关的回溯,Python 3产生了一个不那么令人惊讶的结果:
import traceback
try:
raise TypeError("Oups!")
except Exception as err:
try:
raise TypeError("Again !?!")
except:
pass
traceback.print_tb(err.__traceback__)
... 将显示:
File "e3.py", line 4, in <module>
raise TypeError("Oups!")
你可以这样做:
try:
do_stuff()
except Exception, err:
print(Exception, err)
raise err