From: Hong Minhee <minhee@dahlia.kr>
Date: Fri, 12 Apr 2013 22:00:41 +0000 (+0900)
Subject: Introduce compatibility module
X-Git-Tag: rel_0_6_0~22^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8985077b31c371a3e97c38203a4af36c33728b73;p=thirdparty%2Fsqlalchemy%2Falembic.git

Introduce compatibility module
---

diff --git a/alembic/autogenerate.py b/alembic/autogenerate.py
index 452fe7fe..348079a0 100644
--- a/alembic/autogenerate.py
+++ b/alembic/autogenerate.py
@@ -1,18 +1,16 @@
 """Provide the 'autogenerate' feature which can produce migration operations
 automatically."""
 
-try:
-    import builtins
-except ImportError:
-    import __builtin__ as builtins
 import logging
 import re
 
-from . import util
 from sqlalchemy.engine.reflection import Inspector
 from sqlalchemy.util import OrderedSet
 from sqlalchemy import schema as sa_schema, types as sqltypes
 
+from . import util
+from .compat import string_types
+
 log = logging.getLogger(__name__)
 
 ###################################################
@@ -588,18 +586,17 @@ def _render_column(column, autogen_context):
     }
 
 def _render_server_default(default, autogen_context):
-    string_type = getattr(builtins, 'basestring', str)
     rendered = _user_defined_render("server_default", default, autogen_context)
     if rendered is not False:
         return rendered
 
     if isinstance(default, sa_schema.DefaultClause):
-        if isinstance(default.arg, string_type):
+        if isinstance(default.arg, string_types):
             default = default.arg
         else:
             default = str(default.arg.compile(
                             dialect=autogen_context['dialect']))
-    if isinstance(default, string_type):
+    if isinstance(default, string_types):
         # TODO: this is just a hack to get
         # tests to pass until we figure out
         # WTF sqlite is doing
diff --git a/alembic/compat.py b/alembic/compat.py
new file mode 100644
index 00000000..6619cb44
--- /dev/null
+++ b/alembic/compat.py
@@ -0,0 +1,29 @@
+import sys
+
+
+py3k = sys.version_info >= (3, 0)
+py3kwarning = getattr(sys, 'py3kwarning', False) or py3k
+py26 = sys.version_info >= (2, 6)
+jython = sys.platform.startswith('java')
+win32 = sys.platform.startswith('win')
+pypy = hasattr(sys, 'pypy_version_info')
+
+if py3k:
+    import builtins as compat_builtins
+    string_types = str,
+    binary_type = bytes
+    text_type = str
+else:
+    import __builtin__ as compat_builtins
+    string_types = basestring,
+    binary_type = str
+    text_type = unicode
+
+
+################################################
+# cross-compatible metaclass implementation
+# Copyright (c) 2010-2012 Benjamin Peterson
+def with_metaclass(meta, base=object):
+    """Create a base class with a metaclass."""
+    return meta("%sBase" % meta.__name__, (base,), {})
+################################################
diff --git a/alembic/ddl/impl.py b/alembic/ddl/impl.py
index af93349c..ab67e0c7 100644
--- a/alembic/ddl/impl.py
+++ b/alembic/ddl/impl.py
@@ -8,6 +8,7 @@ from sqlalchemy.ext.compiler import compiles
 from sqlalchemy import schema, text
 from sqlalchemy import types as sqltypes
 
+from ..compat import string_types, text_type, with_metaclass
 from .. import util
 from . import base
 
@@ -20,7 +21,7 @@ class ImplMeta(type):
 
 _impls = {}
 
-class DefaultImpl(ImplMeta('_ImplBase', (object,), {})):
+class DefaultImpl(with_metaclass(ImplMeta)):
     """Provide the entrypoint for major migration operations,
     including database-specific behavioral variances.
 
@@ -54,7 +55,7 @@ class DefaultImpl(ImplMeta('_ImplBase', (object,), {})):
         return _impls[dialect.name]
 
     def static_output(self, text):
-        text_ = getattr(builtins, 'unicode', str)(text + '\n\n')
+        text_ = text_type(text + '\n\n')
         self.output_buffer.write(text_)
         if callable(getattr(self.output_buffer, 'flush', None)):
             self.output_buffer.flush()
@@ -66,14 +67,13 @@ class DefaultImpl(ImplMeta('_ImplBase', (object,), {})):
     def _exec(self, construct, execution_options=None,
                             multiparams=(),
                             params=util.immutabledict()):
-        if isinstance(construct, getattr(builtins, 'basestring', str)):
+        if isinstance(construct, string_types):
             construct = text(construct)
         if self.as_sql:
             if multiparams or params:
                 # TODO: coverage
                 raise Exception("Execution arguments not allowed with as_sql")
-            unicode = getattr(builtins, 'unicode', str)
-            self.static_output(unicode(
+            self.static_output(text_type(
                     construct.compile(dialect=self.dialect)
                     ).replace("\t", "    ").strip() + self.command_terminator)
         else:
diff --git a/alembic/ddl/mysql.py b/alembic/ddl/mysql.py
index 440eef15..ed48a59f 100644
--- a/alembic/ddl/mysql.py
+++ b/alembic/ddl/mysql.py
@@ -1,17 +1,13 @@
-try:
-    import builtins
-except ImportError:
-    import __builtin__ as builtins
-
 from sqlalchemy.ext.compiler import compiles
 from sqlalchemy import types as sqltypes
 from sqlalchemy import schema
 
+from ..compat import string_types
+from .. import util
 from .impl import DefaultImpl
 from .base import ColumnNullable, ColumnName, ColumnDefault, \
             ColumnType, AlterColumn
 from .base import alter_table
-from .. import util
 
 class MySQLImpl(DefaultImpl):
     __dialect__ = 'mysql'
@@ -94,7 +90,7 @@ def _mysql_alter_column(element, compiler, **kw):
     )
 
 def _render_value(compiler, expr):
-    if isinstance(expr, getattr(builtins, 'basestring', str)):
+    if isinstance(expr, string_types):
         return "'%s'" % expr
     else:
         return compiler.sql_compiler.process(expr)
diff --git a/alembic/operations.py b/alembic/operations.py
index 9f365024..441e54a2 100644
--- a/alembic/operations.py
+++ b/alembic/operations.py
@@ -1,13 +1,10 @@
-try:
-    import builtins
-except ImportError:
-    import __builtin__ as builtins
 from contextlib import contextmanager
 
 from sqlalchemy.types import NULLTYPE, Integer
 from sqlalchemy import schema as sa_schema
 
 from . import util
+from .compat import string_types
 from .ddl import impl
 
 __all__ = ('Operations',)
@@ -147,7 +144,7 @@ class Operations(object):
         ForeignKey.
 
         """
-        if isinstance(fk._colspec, getattr(builtins, 'basestring', str)):
+        if isinstance(fk._colspec, string_types):
             table_key, cname = fk._colspec.rsplit('.', 1)
             sname, tname = self._parse_table_key(table_key)
             if table_key not in metadata.tables:
diff --git a/tests/__init__.py b/tests/__init__.py
index 37f24d33..b838f384 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -22,6 +22,7 @@ from sqlalchemy.util import decorator
 
 import alembic
 from alembic import util
+from alembic.compat import string_types, text_type
 from alembic.migration import MigrationContext
 from alembic.environment import EnvironmentContext
 from alembic.operations import Operations
@@ -96,9 +97,8 @@ def _get_dialect(name):
 
 def assert_compiled(element, assert_string, dialect=None):
     dialect = _get_dialect(dialect)
-    unicode = getattr(builtins, 'unicode', str)
     eq_(
-        unicode(element.compile(dialect=dialect)).\
+        text_type(element.compile(dialect=dialect)).\
                     replace("\n", "").replace("\t", ""),
         assert_string.replace("\n", "").replace("\t", "")
     )
@@ -151,7 +151,7 @@ def assert_raises_message(except_cls, msg, callable_, *args, **kwargs):
         assert False, "Callable did not raise an exception"
     except except_cls as e:
         assert re.search(msg, str(e)), "%r !~ %s" % (msg, e)
-        print(str(e))
+        print(text_type(e))
 
 def op_fixture(dialect='default', as_sql=False):
     impl = _impls[dialect]
@@ -165,11 +165,9 @@ def op_fixture(dialect='default', as_sql=False):
             # as tests get more involved
             self.connection = None
         def _exec(self, construct, *args, **kw):
-            basestring = getattr(builtins, 'basestring', str)
-            unicode = getattr(builtins, 'unicode', str)
-            if isinstance(construct, basestring):
+            if isinstance(construct, string_types):
                 construct = text(construct)
-            sql = unicode(construct.compile(dialect=self.dialect))
+            sql = text_type(construct.compile(dialect=self.dialect))
             sql = re.sub(r'[\n\t]', '', sql)
             self.assertion.append(
                 sql
diff --git a/tests/test_autogenerate.py b/tests/test_autogenerate.py
index 4e8a05f9..c9400294 100644
--- a/tests/test_autogenerate.py
+++ b/tests/test_autogenerate.py
@@ -1,4 +1,3 @@
-
 import re
 import sys
 from unittest import TestCase