make migrate.changeset.databases PEP-8 clean and add it to the API docs

1 files changed, 30 insertions, 12 deletions

diff --git a/migrate/changeset/databases/sqlite.py b/migrate/changeset/databases/sqlite.py
index 0f560c1..caeb1b5 100644
--- a/migrate/changeset/databases/sqlite.py
+++ b/migrate/changeset/databases/sqlite.py
@@ -1,11 +1,18 @@
-from migrate.changeset import ansisql,constraint,exceptions
+"""
+   `SQLite`_ database specific implementations of changeset classes.
+
+   .. _`SQLite`: http://www.sqlite.org/
+"""
+from migrate.changeset import ansisql, constraint, exceptions
 from sqlalchemy.databases import sqlite as sa_base
 from sqlalchemy import Table, MetaData
 #import sqlalchemy as sa
 
 SQLiteSchemaGenerator = sa_base.SQLiteSchemaGenerator
 
+
 class SQLiteHelper(object):
+
     def visit_column(self, param):
         try:
             table = self._to_table(param.table)
@@ -24,50 +31,61 @@ class SQLiteHelper(object):
         self.append('DROP TABLE migration_tmp')
         self.execute()
 
-class SQLiteColumnGenerator(SQLiteSchemaGenerator,ansisql.ANSIColumnGenerator):
+
+class SQLiteColumnGenerator(SQLiteSchemaGenerator,
+                            ansisql.ANSIColumnGenerator):
     pass
 
+
 class SQLiteColumnDropper(SQLiteHelper, ansisql.ANSIColumnDropper):
-    def _modify_table(self,table, column):
+
+    def _modify_table(self, table, column):
         del table.columns[column.name]
-        columns = ','.join([c.name for c in table.columns])
-        return 'INSERT INTO %(table_name)s SELECT ' + columns + ' from migration_tmp'
+        return 'INSERT INTO %(table_name)s SELECT %s from migration_tmp' % \
+            ','.join([c.name for c in table.columns])
+
 
 class SQLiteSchemaChanger(SQLiteHelper, ansisql.ANSISchemaChanger):
-    def _not_supported(self,op):
+
+    def _not_supported(self, op):
         raise exceptions.NotSupportedError("SQLite does not support "
             "%s; see http://www.sqlite.org/lang_altertable.html"%op)
 
     def _modify_table(self, table, delta):
         column = table.columns[delta.current_name]
-        for k,v in delta.items():
+        for k, v in delta.items():
             setattr(column, k, v)
         return 'INSERT INTO %(table_name)s SELECT * from migration_tmp'
 
-    def visit_index(self,param):
+    def visit_index(self, param):
         self._not_supported('ALTER INDEX')
 
     def _do_quote_column_identifier(self, identifier):
         return '"%s"'%identifier
 
+
 class SQLiteConstraintGenerator(ansisql.ANSIConstraintGenerator):
-    def visit_migrate_primary_key_constraint(self,constraint):
+
+    def visit_migrate_primary_key_constraint(self, constraint):
         tmpl = "CREATE UNIQUE INDEX %s ON %s ( %s )"
         cols = ','.join([c.name for c in constraint.columns])
         tname = constraint.table.name
         name = constraint.name
-        msg = tmpl%(name,tname,cols)
+        msg = tmpl % (name, tname, cols)
         self.append(msg)
         self.execute()
 
+
 class SQLiteConstraintDropper(ansisql.ANSIColumnDropper):
-    def visit_migrate_primary_key_constraint(self,constraint):
+
+    def visit_migrate_primary_key_constraint(self, constraint):
         tmpl = "DROP INDEX %s "
         name = constraint.name
-        msg = tmpl%(name)
+        msg = tmpl % (name)
         self.append(msg)
         self.execute()
 
+
 class SQLiteDialect(ansisql.ANSIDialect):
     columngenerator = SQLiteColumnGenerator
     columndropper = SQLiteColumnDropper