[Twisted-Python] eated traceback when decorate method already decorated by inlineCallbacks
Hello to all! Why traceback doesn't include call of g() here? import traceback from twisted.internet import defer, reactor def decor1(f, *argv, **kw): @defer.inlineCallbacks def decor1(): try: res = yield f(*argv, **kw) defer.returnValue(res) except: traceback.print_exc() return decor1 @defer.inlineCallbacks def g(): raise AttributeError yield defer.succeed(1) @decor1 @defer.inlineCallbacks def f(): yield g() f() reactor.run() I see just: Traceback (most recent call last): File "C:\testing\test.py", line 9, in decor1 res = yield f(*argv, **kw) AttributeError
On 09:40 am, sergun@gmail.com wrote:
Hello to all!
Why traceback doesn't include call of g() here?
Tracebacks are tricky, and inlineCallbacks doesn't make them look exactly like they would look if you didn't have Deferreds. twisted.python.failure is a little bit better at handling tracebacks from this sort of code than the traceback module is, so if you write the code like this things will at least be a little better: from twisted.python.failure import Failure def decor1(): try: res = yield f(*argv, **kw) except: Failure.printTraceback() else: defer.returnValue(res) Notice also that I moved returnValue outside of the try block. `returnValue` is implemented using exceptions, so you *must not* catch and handle the exception it raises or it won't work. Jean-Paul
import traceback from twisted.internet import defer, reactor
def decor1(f, *argv, **kw): @defer.inlineCallbacks def decor1(): try: res = yield f(*argv, **kw) defer.returnValue(res) except: traceback.print_exc() return decor1
@defer.inlineCallbacks def g(): raise AttributeError yield defer.succeed(1)
@decor1 @defer.inlineCallbacks def f(): yield g()
f() reactor.run()
I see just: Traceback (most recent call last): File "C:\testing\test.py", line 9, in decor1 res = yield f(*argv, **kw) AttributeError
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14.03.2013, в 18:20, exarkun@twistedmatrix.com написал(а):
On 09:40 am, sergun@gmail.com wrote:
Hello to all!
Why traceback doesn't include call of g() here?
Tracebacks are tricky, and inlineCallbacks doesn't make them look exactly like they would look if you didn't have Deferreds.
twisted.python.failure is a little bit better at handling tracebacks from this sort of code than the traceback module is, so if you write the code like this things will at least be a little better:
from twisted.python.failure import Failure
def decor1(): try: res = yield f(*argv, **kw) except: Failure.printTraceback() else: defer.returnValue(res)
How can I catch failure? In your example you call printTraceback as classmethod but it is instance one.
Notice also that I moved returnValue outside of the try block. `returnValue` is implemented using exceptions, so you *must not* catch and handle the exception it raises or it won't work.
Thanks for that detail!
Jean-Paul
import traceback from twisted.internet import defer, reactor
def decor1(f, *argv, **kw): @defer.inlineCallbacks def decor1(): try: res = yield f(*argv, **kw) defer.returnValue(res) except: traceback.print_exc() return decor1
@defer.inlineCallbacks def g(): raise AttributeError yield defer.succeed(1)
@decor1 @defer.inlineCallbacks def f(): yield g()
f() reactor.run()
I see just: Traceback (most recent call last): File "C:\testing\test.py", line 9, in decor1 res = yield f(*argv, **kw) AttributeError
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participants (3)
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exarkun＠twistedmatrix.com -
Sergey Gerasimov -
Tristan Seligmann