[fileio] Add docstrings

Author: mpsonntag

odml/fileio.py

@@ -4,15 +4,38 @@
 
 
 def load(filename, backend="xml"):
+    """
+    Load an odML document from file.
+    :param filename: Path and filename from where the odML document
+                     is to be loaded and parsed.
+    :param backend: File format of the file containing the odML document.
+                    The default format is XML.
+    :return: The parsed odML document.
+    """
     reader = ODMLReader(backend)
     return reader.from_file(filename)
 
 
 def save(obj, filename, backend="xml"):
+    """
+    Save an open odML document to file of a specified format.
+    :param obj: odML document do be saved.
+    :param filename: Filename and path where the odML document
+                     should be saved.
+    :param backend: Format in which the odML document is to be saved.
+                    The default format is XML.
+    """
     writer = ODMLWriter(backend)
     return writer.write_file(obj, filename)
 
 
 def display(obj, backend="xml"):
+    """
+    Print an open odML document to the command line, formatted in the
+    specified format.
+    :param obj: odML document to be displayed.
+    :param backend: Format in which the odML document is to be displayed.
+                    The default format is XML.
+    """
     writer = ODMLWriter(backend)
     print(writer.to_string(obj))