Re: [Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-06-01 Thread Paul Moore
2008/6/1 Guido van Rossum [EMAIL PROTECTED]: The case for String has already been made. Actually I'm not sure. One you know that isinstance(x, String) is true, what can you assume you can do with x? [...] Right. I'm now beginning to wonder what exactly you're after here -- saying that

Re: [Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-06-01 Thread Guido van Rossum
On Sun, Jun 1, 2008 at 6:57 AM, Paul Moore [EMAIL PROTECTED] wrote: 2008/6/1 Guido van Rossum [EMAIL PROTECTED]: The case for String has already been made. Actually I'm not sure. One you know that isinstance(x, String) is true, what can you assume you can do with x? [...] Right. I'm now

[Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-05-31 Thread Raymond Hettinger
ISTM, the whole reason people are asking for a String ABC is so you can write isinstance(obj, String) and allow registered string-like objects to be accepted. The downside is that everytime you want this for a concrete class or type, it is necessary to write a whole new ABC listing all of the

Re: [Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-05-31 Thread Guido van Rossum
I'm willing to meet you halfway. I really don't want isinstance(x, str) to return True for something that doesn't inherit from the concrete str type; this is bound to lead to too much confusion and breakage. But I'm fine with a String ABC (or any other ABC, e.g. Atomic?) that doesn't define any

Re: [Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-05-31 Thread Nick Coghlan
Raymond Hettinger wrote: If we don't do this, then String won't be the last request. People will want Datetime for example. Pretty much any concrete type could have a look-a-like that wanted its own ABC and for all client code to switch from testing concrete types. If I remember rightly,

Re: [Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-05-31 Thread Guido van Rossum
On Sat, May 31, 2008 at 6:41 PM, Raymond Hettinger [EMAIL PROTECTED] wrote: From: Guido van Rossum [EMAIL PROTECTED] I'm willing to meet you halfway. I really don't want isinstance(x, str) to return True for something that doesn't inherit from the concrete str type; this is bound to lead to

Re: [Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-05-31 Thread Raymond Hettinger
From: Guido van Rossum [EMAIL PROTECTED] I'm willing to meet you halfway. I really don't want isinstance(x, str) to return True for something that doesn't inherit from the concrete str type; this is bound to lead to too much confusion and breakage. Probably true. It was an attractive idea

Re: [Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-05-31 Thread Raymond Hettinger
[Raymond] I propose the following empty abstract classes: String, Datetime, Deque, and Socket. [GvR] Sounds like a mini-PEP is in place. It should focus on the code to actually define these and the intended ways to use them. Okay, will run a Google code search to see if real code exists

Re: [Python-Dev] Alternative to more ABCs [was:] Iterable String Redux (aka String ABC)

2008-05-31 Thread Guido van Rossum
On Sat, May 31, 2008 at 8:09 PM, Raymond Hettinger [EMAIL PROTECTED] wrote: [Raymond] I propose the following empty abstract classes: String, Datetime, Deque, and Socket. [GvR] Sounds like a mini-PEP is in place. It should focus on the code to actually define these and the intended