from
twisted.
internet
import
defer
def
c
(
res
)
:
print
"HELLO!"
raise
Exception
(
)
return
2
def
f
(
_
)
:
print
"HANDLED!"
return
_
def
end
(
_
)
:
print
"END!"
return
_.
value
def
new_f
(
_
)
:
print
"HANDLED 2!"
return
_
def
a
(
)
:
l
=
defer.
Deferred
(
)
l.
addCallbacks
(
c
,
new_f
)
d
=
defer.
Deferred
(
)
d.
addCallback
(
c
)
d.
addErrback
(
f
)
#if you comment this line all works as expected
d.
chainDeferred
(
l
)
d.
addErrback
(
end
)
return
d
a
(
)
.
callback
(
2
)