ENH: Implement to_str method for Python 2/3 compatibility

Author: Licht-T

pandas/compat/__init__.py

@@ -257,6 +257,16 @@ def u(s):
     def u_safe(s):
         return s
 
+    def to_str(s):
+        """
+        Convert bytes and non-string into Python 3 str
+        """
+        if isinstance(s, binary_type):
+            s = bytes_to_str(s)
+        elif not isinstance(s, string_types):
+            s = str(s)
+        return s
+
     def strlen(data, encoding=None):
         # encoding is for compat with PY2
         return len(data)
@@ -302,6 +312,14 @@ def u_safe(s):
         except:
             return s
 
+    def to_str(s):
+        """
+        Convert unicode and non-string into Python 2 str
+        """
+        if not isinstance(s, string_types):
+            s = str(s)
+        return s
+
     def strlen(data, encoding=None):
         try:
             data = data.decode(encoding)