Adding initial version

Author: hackorama

jprops.py

@@ -0,0 +1,53 @@
+"""java properties file parser"""
+
+import re
+
+def getJavaProperties(propfile):
+    """Read the key, element pairs from a java properties file
+
+    Follows the file format 'http://docs.oracle.com/javase/6/docs/api/
+    java/util/Properties.html#load(java.io.Reader)' and tested against
+    the Java 6 version of java.util.Properties
+
+    Args:
+        propfile: a valid file object (as returned by open(filename))
+    Returns:
+        The property key and elements as a dict
+    Raises:
+        IOError: if file operation fails with I/O related reason
+            Corresponds to java IOException in Properties.load()
+        UnicodeDecodeError: if the property file has malformed \uxxxx encoding,
+            Corresponds to java IllegalArgumentException in Properties.load()
+        AttributeError: if invalid object was provided for file object
+            Corresponds to java NullPointerException
+            
+    Author: Kishan Thomas <kishan@hackorama.com>
+    """
+    LINE_BREAKS = '\n\r\f' #end-of-line, carriage-return, form-feed
+    ESC_DELIM = r'\\' # '\'
+    ESCAPED_ESC_DELIM = r'\\\\' # '\\'
+    COMMENT_LINE = re.compile('\s*[#!].*') # starts with #|! ignore white space
+    MULTI_LINE = re.compile(r'.*[\\]\s*$') # ending with '\' ignore white space
+    # non escaped  =|:|' ', include surrounding non escaped white space
+    SPLIT_DELIM = re.compile(r'(?<!\\)\s*(?<!\\)[=: ]\s*')
+    # match escape characters '\', except escaped '\\' and unicode escape '\u'
+    VALID_ESC_DELIM = r'(?<!\\)[\\](?!u)'
+    DEFAULT_ELEMENT = ''
+
+    result = dict()
+    natural_line = propfile.readline()
+    while natural_line:
+        # skip blank lines and comment lines, process only valid logical lines
+        if natural_line.strip() and COMMENT_LINE.match(natural_line) is None:
+            logical_line = natural_line.lstrip().rstrip(LINE_BREAKS)
+            # remove multi line delim and append adjacent lines
+            while MULTI_LINE.match(logical_line): 
+                logical_line = logical_line.rstrip()[:-1] + propfile.readline().lstrip().rstrip(LINE_BREAKS)
+            pair = SPLIT_DELIM.split(logical_line, 1)
+            if len(pair) == 1: pair.append(DEFAULT_ELEMENT)
+            pair = [re.sub(VALID_ESC_DELIM, '', item) for item in pair]
+            pair = [re.sub(ESCAPED_ESC_DELIM, ESC_DELIM, item) for item in pair]
+            pair = [unicode(item, 'unicode_escape') for item in pair] 
+            result[pair[0]] = pair[1] # add key, element to result dict
+        natural_line = propfile.readline()
+    return result