[Python-ideas] "maybe import"?

[Bruce Leban]

On Thu, Dec 26, 2013 at 5:57 PM, Amber Yust <amber.yust at gmail.com> wrote:

> Where the behavior would essentially be as above - attempt to run the
> import normally, and in cases where the import fails, map the name to a
> value of None instead. Users who want a different behavior are still free
> to use the long-form syntax. A possibly variant might be to also only run
> the import if the name isn't already bound,
>

I think you mean do the import if the name is unbound *or bound to
None.* Otherwise,
it doesn't work in the example you gave.

Here's another use case. Some modules, e.g., pycrypto need to be compiled
in order to be installed. I have a stub version of pycrypto which can be
used as a substitute for testing without actually encrypting anything.
Rather than using a new keyword, the try keyword would fit here fine:

try import Crypto
try import CryptoStub as Crypto


note that there are cases where this can't be a drop in replacement:

try import Crypto.Random

try import CryptoStub.Random as Crypto.Random   # not allowed


you'd have to instead write:

try import Crypto.Random as CryptoRandom

try import CryptoStub.Random as CryptoRandom


--- Bruce
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