Tune the partial network expansion flag

The flag has been introduced in [1].

I think it improves things a little for the flag's name to be more
verbose and to require passing it via keyword arguments (otherwise it's
just True or False which is gonna be quite opaque to the reader).

[1] d2f5d05 ("IPNetwork: Allow partial addresses (again) (#377)")

netaddr/ip/__init__.py

@@ -876,7 +876,7 @@ def __bool__(self):
         return True
 
 
-def parse_ip_network(module, addr, flags=0, expand=False):
+def parse_ip_network(module, addr, flags=0, *, expand_partial=False):
     if isinstance(addr, tuple):
         #   CIDR integer tuple
         if len(addr) != 2:
@@ -896,7 +896,7 @@ def parse_ip_network(module, addr, flags=0, expand=False):
             val1 = addr
             val2 = None
 
-        if expand:
+        if expand_partial:
             val1 = module.expand_partial_address(val1)
 
         ip = IPAddress(val1, module.version, flags=INET_PTON)
@@ -972,7 +972,7 @@ class IPNetwork(BaseIP, IPListMixin):
 
     __slots__ = ('_prefixlen',)
 
-    def __init__(self, addr, version=None, flags=0, expand=False):
+    def __init__(self, addr, version=None, flags=0, *, expand_partial=False):
         """
         Constructor.
 
@@ -990,14 +990,14 @@ def __init__(self, addr, version=None, flags=0, expand=False):
             interpretation of the addr value. Currently only supports the
             :data:`NOHOST` option.
 
-        :param expand: (optional) decides whether partial address is
+        :param expand_partial: (optional) decides whether partial address is
             expanded. Currently this is only effective for IPv4 address.
 
             >>> IPNetwork('1.2.3.4/24')
             IPNetwork('1.2.3.4/24')
             >>> IPNetwork('1.2.3.4/24', flags=NOHOST)
             IPNetwork('1.2.3.0/24')
-            >>> IPNetwork('10/24', expand=True)
+            >>> IPNetwork('10/24', expand_partial=True)
             IPNetwork('10.0.0.0/24')
         """
         super(IPNetwork, self).__init__()
@@ -1021,7 +1021,7 @@ def __init__(self, addr, version=None, flags=0, expand=False):
             module = addr._module
             prefixlen = module.width
         elif version == 4:
-            value, prefixlen = parse_ip_network(_ipv4, addr, flags, expand)
+            value, prefixlen = parse_ip_network(_ipv4, addr, flags, expand_partial=expand_partial)
             module = _ipv4
         elif version == 6:
             value, prefixlen = parse_ip_network(_ipv6, addr, flags)
@@ -1031,7 +1031,9 @@ def __init__(self, addr, version=None, flags=0, expand=False):
                 raise ValueError('%r is an invalid IP version!' % version)
             try:
                 module = _ipv4
-                value, prefixlen = parse_ip_network(module, addr, flags, expand)
+                value, prefixlen = parse_ip_network(
+                    module, addr, flags, expand_partial=expand_partial
+                )
             except AddrFormatError:
                 try:
                     module = _ipv6

netaddr/tests/ip/test_ip_v4.py

@@ -355,12 +355,12 @@ def test_ipnetwork_bad_string_constructor():
         IPNetwork('foo')
 
 
-def test_ipnetwork_expand_v4():
+def test_ipnetwork_expand_partial_v4():
     with pytest.raises(AddrFormatError):
         IPNetwork('10/8')
-    assert IPNetwork('10/8', expand=True) == IPNetwork('10.0.0.0/8')
-    assert IPNetwork('10.20/16', expand=True) == IPNetwork('10.20.0.0/16')
-    assert IPNetwork('10.20.30/24', expand=True) == IPNetwork('10.20.30.0/24')
+    assert IPNetwork('10/8', expand_partial=True) == IPNetwork('10.0.0.0/8')
+    assert IPNetwork('10.20/16', expand_partial=True) == IPNetwork('10.20.0.0/16')
+    assert IPNetwork('10.20.30/24', expand_partial=True) == IPNetwork('10.20.30.0/24')
 
 
 def test_ipaddress_netmask_v4():