More informative repr for Repository objects

[takluyver]

Before, with the default Python repr:

<pygit2.repository.Repository at 0x7f3858b1cc00>

After, with a repr that shows how to construct this object (which is recommended where practical):

pygit2.Repository('/home/takluyver/Code/pygit2/.git/')

[pypingou]

Isn't the standard way of doing it more along the lines of <Object ...> ? So maybe <pygit2.Repository '/home/takluyver/Code/pygit2/.git/'> ?

[takluyver]

The docs say "For many types, this function [repr] makes an attempt to return a string that would yield an object with the same value when passed to eval(), otherwise the representation is a string enclosed in angle brackets that contains the name of the type of the object together with additional information often including the name and address of the object."

If the object can practically be reconstructed in a single line of code, the constructor form is generally preferred. In the standard library, classes in the decimal, fractions, collections and ast modules work like this, for example.

[takluyver]

Actually, the docs for the __repr__ method are even clearer: " If at all possible, this should look like a valid Python expression that could be used to recreate an object with the same value (given an appropriate environment)."

[uniphil]

Does a pygit2.Repository store any mutable state in its instance? Or is
all the state on disc in the git db?

Note that for collections drops the module name

>>> from collections import defaultdict
>>> repr(defaultdict(int))
"defaultdict(<type 'int'>, {})"

so just Repository('/home/takluyver/Code/pygit2/.git/') would be
consistent with that.

On Tue, Mar 25, 2014 at 7:03 PM, Thomas Kluyver notifications@gh.neting.ccwrote:

Actually, the docs for the repr method are even clearer: " If at all
possible, this should look like a valid Python expression that could be
used to recreate an object with the same value (given an appropriate
environment)."

Reply to this email directly or view it on GitHubhttps://github.com//pull/352#issuecomment-38632372
.

[takluyver]

Yes, I was assuming that there's no important state stored in the Repository object.

I feel like I've seen modules that keep the module name in as well, though I can't find any at the moment. It seems better to me to be unambiguous, but I'm happy with dropping the module name if others prefer that.

[takluyver]

datetime.datetime is an example of something that puts the module name in the repr.

[takluyver]

Thanks!