web.database now accepts a URL, $DATABASE_URL (fixes webpy#171)

Author: aaronsw

web/db.py

@@ -11,7 +11,7 @@
  "database", 'DB',
 ]
 
-import time
+import time, os
 try:
  import datetime
 except ImportError:
@@ -1131,13 +1131,33 @@ def _process_insert_query(self, query, tablename, seqname):
  else:
  return query + "; SELECT %s.currval FROM dual" % seqname 
 
+def dburl2dict(url):
+ """
+ Takes a URL to a database and parses it into an equivalent dictionary.
+ 
+ >>> dburl2dict('postgres://james:day@serverfarm.example.net:5432/mygreatdb')
+ {'user': 'james', 'host': 'serverfarm.example.net', 'db': 'mygreatdb', 'pw': 'day', 'dbn': 'postgres'}
+ 
+ """
+ dbn, rest = url.split('://', 1)
+ user, rest = rest.split(':', 1)
+ pw, rest = rest.split('@', 1)
+ host, rest = rest.split(':', 1)
+ port, rest = rest.split('/', 1)
+ db = rest
+ return dict(dbn=dbn, user=user, pw=pw, db=db, host=host)
+
 _databases = {}
 def database(dburl=None, **params):
  """Creates appropriate database using params.
  
  Pooling will be enabled if DBUtils module is available. 
  Pooling can be disabled by passing pooling=False in params.
  """
+ if not dburl and not params:
+ dburl = os.environ['DATABASE_URL']
+ if dburl:
+ params = dburl2dict(dburl)
  dbn = params.pop('dbn')
  if dbn in _databases:
  return _databases[dbn](**params)