From e7545c7c40cf1830ceee77cdeb8b04a9d5b3c754 Mon Sep 17 00:00:00 2001
From: INADA Naoki <inada-n@klab.com>
Date: Fri, 18 Apr 2014 23:25:01 +0900
Subject: [PATCH] refactoring.

---
 MySQLdb/compat.py      |  4 ++++
 MySQLdb/connections.py | 13 ++++++++++---
 MySQLdb/converters.py  | 38 +++++++++++---------------------------
 3 files changed, 25 insertions(+), 30 deletions(-)

diff --git a/MySQLdb/compat.py b/MySQLdb/compat.py
index 4d84afe..70580b6 100644
--- a/MySQLdb/compat.py
+++ b/MySQLdb/compat.py
@@ -1,8 +1,12 @@
 import sys
 
 if sys.version_info[0] == 3:
+    PY2 = False
     unicode = str
     unichr = chr
+    long = int
 else:
+    PY2 = True
     unicode = unicode
     unichr = unichr
+    long = long
diff --git a/MySQLdb/connections.py b/MySQLdb/connections.py
index 3c7a977..1b18fa6 100644
--- a/MySQLdb/connections.py
+++ b/MySQLdb/connections.py
@@ -7,7 +7,7 @@ override Connection.default_cursor with a non-standard Cursor class.
 
 """
 from MySQLdb import cursors
-from MySQLdb.compat import unicode
+from MySQLdb.compat import unicode, PY2
 from _mysql_exceptions import Warning, Error, InterfaceError, DataError, \
      DatabaseError, OperationalError, IntegrityError, InternalError, \
      NotSupportedError, ProgrammingError
@@ -15,8 +15,6 @@ import _mysql
 import re
 import sys
 
-PY2 = sys.version_info[0] == 2
-
 
 def defaulterrorhandler(connection, cursor, errorclass, errorvalue):
     """
@@ -123,6 +121,7 @@ class Connection(_mysql.connection):
           columns are returned as strings.  columns are returned as
           normal strings. Unicode objects will always be encoded to
           the connection's character set regardless of this setting.
+          Default to False on Python 2 and True on Python 3.
 
         charset
           If supplied, the connection character set will be changed
@@ -207,15 +206,18 @@ class Connection(_mysql.connection):
 
         db = proxy(self)
         def _get_string_literal():
+            # Note: string_literal() is called for bytes object on Python 3.
             def string_literal(obj, dummy=None):
                 return db.string_literal(obj)
             return string_literal
 
         def _get_unicode_literal():
             if PY2:
+                # unicode_literal is called for only unicode object.
                 def unicode_literal(u, dummy=None):
                     return db.literal(u.encode(unicode_literal.charset))
             else:
+                # unicode_literal() is called for arbitrary object.
                 def unicode_literal(u, dummy=None):
                     return db.literal(str(u).encode(unicode_literal.charset))
             return unicode_literal
@@ -288,6 +290,11 @@ class Connection(_mysql.connection):
 
         """
         s = self.escape(o, self.encoders)
+        # Python 3 doesn't support % operation for bytes object.
+        # We should decode it before using %.
+        # Decoding with ascii and surrogateescape allows convert arbitrary
+        # bytes to unicode and back again.
+        # See http://python.org/dev/peps/pep-0383/
         if not PY2 and isinstance(s, bytes):
             return s.decode('ascii', 'surrogateescape')
         return s
diff --git a/MySQLdb/converters.py b/MySQLdb/converters.py
index 7f6bfb7..9937e25 100644
--- a/MySQLdb/converters.py
+++ b/MySQLdb/converters.py
@@ -35,18 +35,9 @@ MySQL.connect().
 from _mysql import string_literal, escape_sequence, escape_dict, escape, NULL
 from MySQLdb.constants import FIELD_TYPE, FLAG
 from MySQLdb.times import *
+from MySQLdb.compat import PY2, long
 
-try:
-    from types import IntType, LongType, FloatType, NoneType, TupleType, ListType, DictType, InstanceType, \
-        ObjectType, BooleanType
-    PY2 = True
-except ImportError:
-    # Python 3
-    long = int
-    IntType, LongType, FloatType, NoneType = int, long, float, type(None)
-    TupleType, ListType, DictType, InstanceType = tuple, list, dict, None
-    ObjectType, BooleanType = object, bool
-    PY2 = False
+NoneType = type(None)
 
 import array
 
@@ -78,8 +69,6 @@ def Unicode2Str(s, d):
     is connection-dependent."""
     return s.encode()
 
-Long2Int = Thing2Str
-
 def Float2Str(o, d):
     return '%.15g' % o
 
@@ -88,12 +77,10 @@ def None2NULL(o, d):
     return NULL # duh
 
 def Thing2Literal(o, d):
-    
     """Convert something into a SQL string literal.  If using
     MySQL-3.23 or newer, string_literal() is a method of the
     _mysql.MYSQL object, and this function will be overridden with
     that method when the connection is created."""
-
     return string_literal(o, d)
 
 
@@ -107,19 +94,19 @@ def quote_tuple(t, d):
     return "(%s)" % (','.join(escape_sequence(t, d)))
 
 conversions = {
-    IntType: Thing2Str,
-    LongType: Long2Int,
-    FloatType: Float2Str,
+    int: Thing2Str,
+    long: Thing2Str,
+    float: Float2Str,
     NoneType: None2NULL,
-    TupleType: quote_tuple,
-    ListType: quote_tuple,
-    DictType: escape_dict,
+    tuple: quote_tuple,
+    list: quote_tuple,
+    dict: escape_dict,
     ArrayType: array2Str,
-    BooleanType: Bool2Str,
+    bool: Bool2Str,
     Date: Thing2Literal,
     DateTimeType: DateTime2literal,
     DateTimeDeltaType: DateTimeDelta2literal,
-    str: str,  # default
+    str: Thing2Literal,  # default
     set: Set2Str,
     FIELD_TYPE.TINY: int,
     FIELD_TYPE.SHORT: int,
@@ -152,7 +139,7 @@ conversions = {
 if PY2:
     conversions[unicode] = Unicode2Str
 else:
-    conversions[bytes] = bytes
+    conversions[bytes] = Thing2Literal
 
 try:
     from decimal import Decimal
@@ -160,6 +147,3 @@ try:
     conversions[FIELD_TYPE.NEWDECIMAL] = Decimal
 except ImportError:
     pass
-
-
-