test/data/vclamp_jpk/README: Document sample versions

[hooke.git] / hooke / util / convert.py

diff --git a/hooke/util/convert.py b/hooke/util/convert.py
index 44955a574791a9fd04f6d717b2daae45a6960cdc..32d2bd5905495dcd9d87dd2f79ded4272deee6ef 100644 (file)
--- a/hooke/util/convert.py
+++ b/hooke/util/convert.py
@@ -1,16 +1,23 @@
-# Copyright
+# Copyright (C) 2010-2012 W. Trevor King <wking@tremily.us>
+#
+# This file is part of Hooke.
+#
+# Hooke is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option) any
+# later version.
+#
+# Hooke is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Hooke.  If not, see <http://www.gnu.org/licenses/>.
 
 """Type conversion utilities.
 """
 
-CONVERT_FROM_STRING = {
-    'string': lambda x: x,
-    'bool': lambda x: x == 'True',
-    'int': lambda x: int(x),
-    'float': lambda x: float(x),
-    }
-"""Functions converting strings to values, keyed by type.
-"""
 
 ANALOGS = {
     'file': 'string',
@@ -47,6 +54,23 @@ def to_string(value, type, count=1):
 
 def from_string(value, type, count=1):
     """Convert `value` from a string to `type`.
+
+    Examples
+    --------
+    >>> from_string('abcde', type='string')
+    u'abcde'
+    >>> from_string('None', type='string')
+    >>> from_string(None, type='string')
+    >>> from_string('true', type='bool')
+    True
+    >>> from_string('false', type='bool')
+    False
+    >>> from_string(None, type='bool')
+    False
+    >>> from_string('123', type='int')
+    123
+    >>> from_string('123', type='float')
+    123.0
     """
     type = ANALOGS.get(type, type)
     if type in RAW_TYPES:
@@ -63,13 +87,19 @@ def from_string(value, type, count=1):
     return fn(value)
 
 def _string_to_string(value):
+    if value in [None, 'None'] or len(value) == 0:
+        return None
     return unicode(value)
 
 def _string_to_bool(value):
-    return value == 'True'
+    return hasattr(value, 'lower') and value.lower() == 'true'
 
 def _string_to_int(value):
+    if value in [None, 'None']:
+        return None
     return int(value)
 
 def _string_to_float(value):
+    if value in [None, 'None']:
+        return None
     return float(value)