[Python-Dev] For review: PEP 285: Adding a bool type (original) (raw)

Guido van Rossum guido@python.org
Fri, 08 Mar 2002 13:49:26 -0500

That's the main argument for adding a boolean type to the language. We already have the singletons...

In C, not in Python!

mxODBC in SQL binding mode. Some databases only allow passing in strings, so mxODBC has to call str(obj) to pass the object stringified to the database.

This works just fine with PyTrue and PyFalse, since DBs know that 1 and 0 are true and false. I'm not sure how well 'True' and 'False' would work here, ODBC doesn't say anything on these values if used in the C API, in fact it doesn't have a native BOOLEAN type, just a BIT.

OK, so you may have to change one line in one module.

Perhaps you could clarify the need for these new str and repr values ?!

I'd be happy with repr(True) giving me 'True', but not str(True).

It just seems to make more sense if booleans print as True and False. But if that really is going to be the only place where things break, I'm willing to reconsider this.

No. The point is that printing truth values up to now has always resulted in '0' or '1'. You are about to change that to 'True' and 'False'. This can create a l10n issue in existing applications.

An application that prints the digits 0 or 1 to mean true or false doesn't sound very user-friendly to me either. I'm not worried that we'll get actual complaints from people that this broke their program.

It may also cause applications which write out boolean data this way to fail, e.g. report generation tools, XML generators, database extraction tools, etc... Just think of code like this:

print '' % (x != 0) (It's not like I'm running out of arguments :-)

We'll see. :-)

--Guido van Rossum (home page: http://www.python.org/~guido/)