engine.url cleanups [ticket:742]

- translate_connect_args can now take kw args or the classic list
- in-tree dialects updated to supply their overrides as keywords
- tweaked url parsing in the spirit of the #742 patch, more or less

1 files changed, 51 insertions, 31 deletions

diff --git a/lib/sqlalchemy/engine/url.py b/lib/sqlalchemy/engine/url.py
index 1f6f9eff4..a3487638c 100644
--- a/lib/sqlalchemy/engine/url.py
+++ b/lib/sqlalchemy/engine/url.py
@@ -101,24 +101,40 @@ class URL(object):
             return dialect
         raise ImportError('unknown database %r' % self.drivername) 
   
-    def translate_connect_args(self, names):
-        """Translate attributes into a dictionary of connection arguments.
-
-        Given a list of argument names corresponding to the URL
-        attributes (`host`, `database`, `username`, `password`,
-        `port`), will assemble the attribute values of this URL into
-        the dictionary using the given names.
+    def translate_connect_args(self, names=[], **kw):
+        """Translate url attributes into a dictionary of connection arguments.
+
+        Returns attributes of this url (`host`, `database`, `username`,
+        `password`, `port`) as a plain dictionary.  The attribute names are
+        used as the keys by default.  Unset or false attributes are omitted
+        from the final dictionary.
+
+        \**kw
+          Optional, alternate key names for url attributes::
+
+            # return 'username' as 'user'
+            username='user'
+
+            # omit 'database'
+            database=None
+          
+        names
+          Deprecated.  A list of key names. Equivalent to the keyword
+          usage, must be provided in the order above.
         """
 
-        a = {}
+        translated = {}
         attribute_names = ['host', 'database', 'username', 'password', 'port']
-        for n in names:
-            sname = attribute_names.pop(0)
-            if n is None:
-                continue
-            if getattr(self, sname, None):
-                a[n] = getattr(self, sname)
-        return a
+        for sname in attribute_names:
+            if names:
+                name = names.pop(0)
+            elif sname in kw:
+                name = kw[sname]
+            else:
+                name = sname
+            if name is not None and getattr(self, sname, False):
+                translated[name] = getattr(self, sname)
+        return translated
 
 def make_url(name_or_url):
     """Given a string or unicode instance, produce a new URL instance.
@@ -134,36 +150,40 @@ def make_url(name_or_url):
 
 def _parse_rfc1738_args(name):
     pattern = re.compile(r'''
-            (\w+)://
+            (?P<name>\w+)://
             (?:
-                ([^:/]*)
-                (?::([^/]*))?
+                (?P<username>[^:/]*)
+                (?::(?P<password>[^/]*))?
             @)?
             (?:
-                ([^/:]*)
-                (?::([^/]*))?
+                (?P<host>[^/:]*)
+                (?::(?P<port>[^/]*))?
             )?
-            (?:/(.*))?
+            (?:/(?P<database>.*))?
             '''
             , re.X)
 
     m = pattern.match(name)
     if m is not None:
-        (name, username, password, host, port, database) = m.group(1, 2, 3, 4, 5, 6)
-        if database is not None:
-            tokens = database.split(r"?", 2)
-            database = tokens[0]
-            query = (len(tokens) > 1 and dict( cgi.parse_qsl(tokens[1]) ) or None)
+        components = m.groupdict()
+        if components['database'] is not None:
+            tokens = components['database'].split('?', 2)
+            components['database'] = tokens[0]
+            query = (len(tokens) > 1 and dict(cgi.parse_qsl(tokens[1]))) or None
             if query is not None:
                 query = dict([(k.encode('ascii'), query[k]) for k in query])
         else:
             query = None
-        opts = {'username':username,'password':password,'host':host,'port':port,'database':database, 'query':query}
-        if opts['password'] is not None:
-            opts['password'] = urllib.unquote_plus(opts['password'])
-        return URL(name, **opts)
+        components['query'] = query
+
+        if components['password'] is not None:
+            components['password'] = urllib.unquote_plus(components['password'])
+
+        name = components.pop('name')
+        return URL(name, **components)
     else:
-        raise exceptions.ArgumentError("Could not parse rfc1738 URL from string '%s'" % name)
+        raise exceptions.ArgumentError(
+            "Could not parse rfc1738 URL from string '%s'" % name)
 
 def _parse_keyvalue_args(name):
     m = re.match( r'(\w+)://(.*)', name)