update public distribution

based on internal repository c9a2ac8 2019-01-03 16:04:57 +0100
tagged rev-master-2.0.0

pmsco/compat.py

@@ -0,0 +1,40 @@
+"""
+@package pmsco.compat
+compatibility code
+
+code bits to provide compatibility for different python versions.
+currently supported 2.7 and 3.6.
+"""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from io import open as io_open
+
+
+def open(fname, mode='r', encoding='latin1'):
+    """
+    open a data file for read/write/append using the default str type
+
+    this is a drop-in for io.open
+    where data is exchanged via the built-in str type of python,
+    whether this is a byte string (python 2) or unicode string (python 3).
+
+    the file is assumed to be a latin-1 encoded binary file.
+
+    @param fname: file name and path
+    @param mode: 'r', 'w' or 'a'
+    @param encoding: 'latin1' (default), 'ascii' or 'utf-8'
+    @return file handle
+    """
+    if isinstance(b'b', str):
+        # python 2
+        mode += 'b'
+        kwargs = {}
+    else:
+        # python 3
+        mode += 't'
+        kwargs = {'encoding': encoding}
+
+    return io_open(fname, mode, **kwargs)