apache module rewritten for py3 compat

* added 'encoding' kwd to Htpasswd, Htdigest constructors,
  allowing user/realm encoding to be specified.
* treats file as bytes internally
* added UTs for encoding-specific behavior
* added render_bytes() util helper - py2/3 compatible replacement for using % formatting with bytes

1 files changed, 20 insertions, 0 deletions

diff --git a/passlib/utils/__init__.py b/passlib/utils/__init__.py
index e0c683f..e1ffc34 100644
--- a/passlib/utils/__init__.py
+++ b/passlib/utils/__init__.py
@@ -488,6 +488,26 @@ def bjoin_ints(values):
 #bjoin_ints = bytes
 # end Py3k #
 
+def render_bytes(source, *args):
+    """helper for using formatting operator with bytes.
+    
+    this function is motivated by the fact that
+    :class:`bytes` instances do not support % or {} formatting under python 3.
+    this function is an attempt to provide a replacement
+    that will work uniformly under python 2 & 3.
+    
+    it converts everything to unicode (including bytes arguments),
+    then encodes the result to latin-1.
+    """
+    if isinstance(source, bytes):
+        source = source.decode("latin-1")
+    def adapt(arg):
+        if isinstance(arg, bytes):
+            return arg.decode("latin-1")
+        return arg
+    result = source % tuple(adapt(arg) for arg in args)
+    return result.encode("latin-1")
+
 #=================================================================================
 #numeric helpers
 #=================================================================================