Below is typical feedback to a student.
What do others think regarding my discussion of using try /except
in routine dict manipulation?
Kirby
===
Yes perfect. Good work.
try:
res_dict[ext] += 1
except KeyError:
res_dict[ext] = 1
This code is not atypical and you'll find some polarization among
Pythonistas about whether this is good style. Another construct:
res_dict[ext] = res_dict.get(ext, 0) + 1
is the one I favor. I think of a "key not found" event
in a dict as "routine, to be expected" whereas I think of
try: / except: as for "crying wolf" (not for everyday
contingencies). The opposite bias is: why make that
distinction, try: / except: is a perfectly reasonable
construct for trapping a new key to a dict.
In any case, good Python.
-Kirby
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