[Python-Dev] os.path.join failure mode (original) (raw)

R. David Murray rdmurray at bitdance.com
Sat Feb 9 18:15:28 CET 2013

On Sat, 09 Feb 2013 14:35:33 +0000, Thomas Scrace <tom at scrace.org> wrote:

R. David Murray <rdmurray bitdance.com> writes:

> The reason we avoid such type checks is that we prefer to operate via > "duck typing", which means that if an object behaves like the expected > input, it is accepted. Here, if we did an explicit type check for str, > it would prevent join from working on an "act alike" object that had > just enough str like methods to work correctly in os.join (for example, > some specialized object that was among other things a filename proxy). I see, that makes sense. Thanks. I guess this actually goes to the heart of the flexibility of dynamic/weakly-typed languages. If we wanted to strictly enforce the type of a function's arguments we would use a strong type system.

No, it is more the difference between statically typed and dynamically typed. Python is a strongly typed language (every object has a specific type).

--David

More information about the Python-Dev mailing list