Ben Finney <ben+python@benfinney.id.au> wrote:
Aaron Rubin <aaron.rubin@4dtechnology.com> writes:
Regarding this and the other notion of 5 or 6 being the proper level of indentation:
class a(object): def method1(simulation=False): try: if simulation: for x in range(10): if x>5: try: # here might begin some actual math, with two or three more levels of logic, interfacing with other libraries such as NumPy, etc. where you might need specific error handling except CustomError: # customer error handling
This is fairly clearly a contrived example. Can you give an example of actual in-use code which suffers from such deep indentation?
From threading.py:
class Thread(_Verbose): def __bootstrap_inner(self): try: self.__ident = _get_ident() self.__started.set() _active_limbo_lock.acquire() _active[self.__ident] = self del _limbo[self] _active_limbo_lock.release() if __debug__: self._note("%s.__bootstrap(): thread started", self) if _trace_hook: self._note("%s.__bootstrap(): registering trace hook", self) _sys.settrace(_trace_hook) if _profile_hook: self._note("%s.__bootstrap(): registering profile hook", self) _sys.setprofile(_profile_hook) try: self.run() except SystemExit: if __debug__: self._note("%s.__bootstrap(): raised SystemExit", self) except: if __debug__: self._note("%s.__bootstrap(): unhandled exception", self) # If sys.stderr is no more (most likely from interpreter # shutdown) use self.__stderr. Otherwise still use sys (as in # _sys) in case sys.stderr was redefined since the creation of # self. if _sys: _sys.stderr.write("Exception in thread %s:\n%s\n" % (self.name, _format_exc())) else: # Do the best job possible w/o a huge amt. of code to # approximate a traceback (code ideas from # Lib/traceback.py) exc_type, exc_value, exc_tb = self.__exc_info() try: print>>self.__stderr, ( "Exception in thread " + self.name + " (most likely raised during interpreter shutdown):") print>>self.__stderr, ( "Traceback (most recent call last):") while exc_tb: print>>self.__stderr, ( ' File "%s", line %s, in %s' % (exc_tb.tb_frame.f_code.co_filename, exc_tb.tb_lineno, exc_tb.tb_frame.f_code.co_name)) exc_tb = exc_tb.tb_next print>>self.__stderr, ("%s: %s" % (exc_type, exc_value)) # Make sure that exc_tb gets deleted since it is a memory # hog; deleting everything else is just for thoroughness finally: del exc_type, exc_value, exc_tb else: if __debug__: self._note("%s.__bootstrap(): normal return", self) finally: # Prevent a race in # test_threading.test_no_refcycle_through_target when # the exception keeps the target alive past when we # assert that it's dead. self.__exc_clear() finally: with _active_limbo_lock: self.__stop() try: # We don't call self.__delete() because it also # grabs _active_limbo_lock. del _active[_get_ident()] except: pass Cheers, Cesare