morro

sqlalchemy/processors.py

@@ -0,0 +1,101 @@
+# processors.py
+# Copyright (C) 2010 Gaetan de Menten gdementen@gmail.com
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: http://www.opensource.org/licenses/mit-license.php
+
+"""defines generic type conversion functions, as used in bind and result 
+processors.
+
+They all share one common characteristic: None is passed through unchanged.
+
+"""
+
+import codecs
+import re
+import datetime
+
+def str_to_datetime_processor_factory(regexp, type_):
+    rmatch = regexp.match
+    # Even on python2.6 datetime.strptime is both slower than this code
+    # and it does not support microseconds.
+    def process(value):
+        if value is None:
+            return None
+        else:
+            return type_(*map(int, rmatch(value).groups(0)))
+    return process
+
+try:
+    from sqlalchemy.cprocessors import UnicodeResultProcessor, \
+                                       DecimalResultProcessor, \
+                                       to_float, to_str, int_to_boolean, \
+                                       str_to_datetime, str_to_time, \
+                                       str_to_date
+
+    def to_unicode_processor_factory(encoding, errors=None):
+        # this is cumbersome but it would be even more so on the C side
+        if errors is not None:
+            return UnicodeResultProcessor(encoding, errors).process
+        else:
+            return UnicodeResultProcessor(encoding).process
+    
+    def to_decimal_processor_factory(target_class, scale=10):
+        # Note that the scale argument is not taken into account for integer
+        # values in the C implementation while it is in the Python one. 
+        # For example, the Python implementation might return 
+        # Decimal('5.00000') whereas the C implementation will 
+        # return Decimal('5'). These are equivalent of course.
+        return DecimalResultProcessor(target_class, "%%.%df" % scale).process
+
+except ImportError:
+    def to_unicode_processor_factory(encoding, errors=None):
+        decoder = codecs.getdecoder(encoding)
+
+        def process(value):
+            if value is None:
+                return None
+            else:
+                # decoder returns a tuple: (value, len). Simply dropping the
+                # len part is safe: it is done that way in the normal
+                # 'xx'.decode(encoding) code path.
+                return decoder(value, errors)[0]
+        return process
+
+    def to_decimal_processor_factory(target_class, scale=10):
+        fstring = "%%.%df" % scale
+
+        def process(value):
+            if value is None:
+                return None
+            else:
+                return target_class(fstring % value)
+        return process
+
+    def to_float(value):
+        if value is None:
+            return None
+        else:
+            return float(value)
+
+    def to_str(value):
+        if value is None:
+            return None
+        else:
+            return str(value)
+
+    def int_to_boolean(value):
+        if value is None:
+            return None
+        else:
+            return value and True or False
+
+    DATETIME_RE = re.compile("(\d+)-(\d+)-(\d+) (\d+):(\d+):(\d+)(?:\.(\d+))?")
+    TIME_RE = re.compile("(\d+):(\d+):(\d+)(?:\.(\d+))?")
+    DATE_RE = re.compile("(\d+)-(\d+)-(\d+)")
+
+    str_to_datetime = str_to_datetime_processor_factory(DATETIME_RE,
+                                                        datetime.datetime)
+    str_to_time = str_to_datetime_processor_factory(TIME_RE, datetime.time)
+    str_to_date = str_to_datetime_processor_factory(DATE_RE, datetime.date)
+