Warn if argument is not a subclass of unicode

1 files changed, 8 insertions, 0 deletions

diff --git a/unidecode/__init__.py b/unidecode/__init__.py
index 4a08bf0..f86fb03 100644
--- a/unidecode/__init__.py
+++ b/unidecode/__init__.py
@@ -13,6 +13,9 @@ In Python 3, a standard string object will be returned. If you need bytes, use:
 >>> unidecode("Κνωσός").encode("ascii")
 b'Knosos'
 """
+import warnings
+from sys import version_info
+
 Cache = {}
 
 def unidecode(string):
@@ -22,6 +25,11 @@ def unidecode(string):
     "Bei Jing "
     """
 
+    if version_info[0] < 3 and not isinstance(string, unicode):
+        warnings.warn(  "Argument %r is not an unicode object. "
+                        "Passing an encoded string will likely have "
+                        "unexpected results." % (type(string),) , RuntimeWarning)
+
     retval = []
 
     for char in string: