Hi all,
Imagine I have three functions a(x), b(x), c(x) that each return
something or raise an exception. Imagine I want to define a function
that returns a(x) if possible, otherwise b(x), otherwise c(x),
otherwise raise CantDoIt.
Here are three ways I can think of doing it:
----------
# This one looks ugly
def nested_first(x):
try:
return a(x)
except:
try:
return b(x)
except:
try:
return c(x)
except:
raise CantDoIt
# This one looks long-winded
def flat_first(x):
try:
return a(x)
except:
pass
try:
return b(x)
except:
pass
try:
return c(x)
except:
raise CantDoIt
# This one only works because a,b,c are functions
# Moreover it seems like an abuse of a loop construct to me
def rolled_first(x):
for f in a, b, c:
try:
return f(x)
except:
continue
raise CantDoIt
----------
I don't feel happy with any of these. Is there a more satisfying way
of doing this in Python? What I would like is something like:
----------
# This one isn't correct but looks the clearest to me
def wished_first(x):
try:
return a(x)
except:
return b(x)
except:
return c(x)
except:
raise CantDoIt
----------
I guess what I'm looking for is some sort of
if:
elif:
...
elif:
else:
but for try: except:
That's why
try:
except:
except:
...
except:
seemed natural to me :) And I'd like to find a nice way to do this in
a syntactically correct way.
Note: I've chosen functions a, b, c, but really I'm looking for a way
that is suitable for any chunk of code.
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