Lib/ipaddress.py does not implement is_global for IPv4Address, in contrast to the documentation which states for IPv4Address.is_global: "True if the address is allocated for public networks."

A patch like the one attached to this report should fix that.

The patch looks correct to me, but we also need tests.

New patch includes tests.

Lightly tested with Python 3.4 (because trunk doesn't build for me right now): tests fail without patch, pass with patch.

Patch re-diffed against trunk.

+    @property
+    def is_global(self):
+        return (not self in IPv4Network('100.64.0.0/10') and

Can IPv4Network('100.64.0.0/10') moved to the _IPv4Constants class (e.g. _IPv4Constants._global_network = IPv4Network('100.64.0.0/10')) after http://hg.python.org/cpython/rev/e5d963cb6afc (see also issue 21513)

+                not self.is_private)

Seeing that the patch merged for issue 21513 left the existing test for 100.64.0.0 (IPv4 network) untouched, I think it would make more sense to make that address a constant everywhere in a separate patch (if that is indeed desirable).

Here is an updated patch that uses my proposal in msg219017. Since this is already documented at https://docs.python.org/3.5/library/ipaddress.html#ipaddress.IPv4Address.is_global I think it should also go into 3.5.

New changeset d65191861599 by Berker Peksag in branch '3.5':
Issue #21386: Implement missing IPv4Address.is_global property
https://hg.python.org/cpython/rev/d65191861599

New changeset 1519ca772e54 by Berker Peksag in branch 'default':
Issue #21386: Merge from 3.5
https://hg.python.org/cpython/rev/1519ca772e54

Thanks Roger!