[Python-Dev] Chaining try statements: eltry? (original) (raw)

Raymond Hettinger python at rcn.com
Wed Jul 6 22:06:06 CEST 2005

[Thomas Lotze]

> I want to ask what you think about introducing a keyword 'eltry' > which would be the counterpart of 'elif' for try statements. This > had been suggested before on python-list a couple of years ago by > Jonathan Gardner, but nothing (that I could find) seems to have come

> of it.

[Guido]

I'm -1 on this. The use case doesn't occur often in my experience and IMO putting each try statement in the else clause of the previous one is a fine solution.

I also notice that your only example is very repetitive, and would be better written as a loop, using Python's dynamic nature: for decoder in foodecode, bardecode, foobardecode: try: data = decoder(data) break except ValueError: print "data doesn't seem to be %s-encoded" % decoder.name

FWIW, the looping solution has worked out well in practice. From csv.py:

for thisType in [int, long, float, complex]:
    try:
        thisType(row[col])
        break
    except (ValueError, OverflowError):
        pass

Raymond

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