update from Atlas

support/isis2json/subfield.py

@@ -0,0 +1,142 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8 -*-
+
+# ISIS-DM: the ISIS Data Model API
+#
+# Copyright (C) 2010 BIREME/PAHO/WHO
+#
+# This program 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 2.1 of the License, or
+# (at your option) any later version.
+
+# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+
+from collections import namedtuple
+import re
+
+
+MAIN_SUBFIELD_KEY = '_'
+SUBFIELD_MARKER_RE = re.compile(r'\^([a-z0-9])', re.IGNORECASE)
+DEFAULT_ENCODING = u'utf-8'
+
+def expand(content, subkeys=None):
+    ''' Parse a field into an association list of keys and subfields
+
+        >>> expand('zero^1one^2two^3three')
+        [('_', 'zero'), ('1', 'one'), ('2', 'two'), ('3', 'three')]
+
+    '''
+    if subkeys is None:
+        regex = SUBFIELD_MARKER_RE
+    elif subkeys == '':
+        return [(MAIN_SUBFIELD_KEY, content)]
+    else:
+        regex = re.compile(r'\^(['+subkeys+'])', re.IGNORECASE)
+    content = content.replace('^^', '^^ ')
+    parts = []
+    start = 0
+    key = MAIN_SUBFIELD_KEY
+    while True:
+        found = regex.search(content, start)
+        if found is None: break
+        parts.append((key, content[start:found.start()].rstrip()))
+        key = found.group(1).lower()
+        start = found.end()
+    parts.append((key, content[start:].rstrip()))
+    return parts
+
+
+class CompositeString(object):
+    ''' Represent an Isis field, with subfields, using
+    Python native datastructures
+
+    >>> author = CompositeString('John Tenniel^xillustrator',
+    ... subkeys='x')
+    >>> unicode(author)
+    u'John Tenniel^xillustrator'
+    '''
+    
+    def __init__(self, isis_raw, subkeys=None, encoding=DEFAULT_ENCODING):
+        if not isinstance(isis_raw, basestring):
+            raise TypeError('%r value must be unicode or str instance' % isis_raw)
+
+        self.__isis_raw = isis_raw.decode(encoding)
+        self.__expanded = expand(self.__isis_raw, subkeys)
+
+    def __getitem__(self, key):
+        for subfield in self.__expanded:
+            if subfield[0] == key:
+                return subfield[1]
+        else:
+            raise KeyError(key)
+
+    def __iter__(self):
+        return (subfield[0] for subfield in self.__expanded)
+
+    def items(self):
+        return self.__expanded
+
+    def __unicode__(self):
+        return self.__isis_raw
+
+    def __str__(self):
+        return str(self.__isis_raw)
+
+
+class CompositeField(object):
+    ''' Represent an Isis field, with subfields, using
+        Python native datastructures
+
+        >>> author = CompositeField( [('name','Braz, Marcelo'),('role','writer')] )
+        >>> print author['name']
+        Braz, Marcelo
+        >>> print author['role']
+        writer
+        >>> author
+        CompositeField((('name', 'Braz, Marcelo'), ('role', 'writer')))
+
+    '''
+
+    def __init__(self, value, subkeys=None):
+        if subkeys is None:
+            subkeys = [item[0] for item in value]
+        try:
+            value_as_dict = dict(value)
+        except TypeError:
+            raise TypeError('%r value must be a key-value structure' % self)
+        
+        for key in value_as_dict:
+            if key not in subkeys:
+                raise TypeError('Unexpected keyword %r' % key)
+    
+        self.value = tuple([(key, value_as_dict.get(key,None)) for key in subkeys])
+
+    def __getitem__(self, key):
+        return dict(self.value)[key]
+
+    def __repr__(self):
+        return "CompositeField(%s)" % str(self.items())
+
+    def items(self):
+        return self.value
+
+    def __unicode__(self):
+        unicode(self.items())
+
+    def __str__(self):
+        str(self.items())
+
+
+def test():
+    import doctest
+    doctest.testmod()
+
+if __name__=='__main__':
+    test()