Fixing the issue that way excludes Python 2.7.

Better would be:

try:
    from collections.abc import Callable
except ImportError:
    from collections import Callable

and then to use Callable directly.

Dear Andy,

Python 2.7 first came out on 2010. Its EOL was announced for almost 2 years ago. If we're to carry all these corpses in the trunk, we might as well work for the Corleone family. I'm going to risk saying that this is no longer the same language.

Now, I have very little idea what amount of trouble this would involve, but could this not simply be a pyreadline version bump, featuring end of support for Python 2? This way, users still stuck with the Two (few but not zero, I know) could have their own stable version.

I could not emphasize this loud enough: if you are a command-line animal like me, this is one of the most useful libraries in the whole Pyverse. As I mentioned, this is working great for me. I just want it to work great for everybody.

Although, if we were about to carry all these corpses, then…
collections.abc is new since version 3.3, so in my humble opinion the best solution would be:

if sys.version_info[:2] >= (3, 3):
    from collections.abc import Callable
else:
    from collections import Callable
    
def callable(x):
    return isinstance(x, Callable)

But to be honest, I pretty much agree with @ricardo-reis-1970.

But to be honest, I pretty much agree with @ricardo-reis-1970.

You mean my code suggestion or my opinion on pyreadline? 😉

Please send your PR here

Although, if we were about to carry all these corpses, then… collections.abc is new since version 3.3, so in my humble opinion the best solution would be:

if sys.version_info[:2] >= (3, 3):
    from collections.abc import Callable
else:
    from collections import Callable
    
def callable(x):
    return isinstance(x, Callable)

Bumping -- I like this solution.

Fixing the issue that way excludes Python 2.7.

Better would be:

try:
    from collections.abc import Callable
except ImportError:
    from collections import Callable

and then to use Callable directly.

This codepath is not executed for Python 2, only Python 3:

...
if sys.version_info[0] >= 3:
    import collections
    PY3 = True
    def callable(x):
        return isinstance(x, collections.Callable)  # The offnding line

    def execfile(fname, glob, loc=None):
        loc = loc if (loc is not None) else glob
        with open(fname) as fil:
            txt = fil.read()
        exec(compile(txt, fname, 'exec'), glob, loc)
    unicode = str
    bytes = bytes
    from io import StringIO
else:
    PY3 = False
    ...