Fazendo uma conversão simples para evitar erros de unicode

pytrustnfe/xml/filters.py

@@ -24,6 +24,8 @@ def normalize_str(string):
 
 def strip_line_feed(string):
     if string:
+        if not isinstance(string, unicode):
+            string = unicode(string, 'utf-8', 'replace')
         remap = {
             ord(u'\t'): u' ',
             ord(u'\n'): u' ',

setup.py

@@ -1,7 +1,7 @@
 # coding=utf-8
 from setuptools import setup, find_packages
 
-VERSION = "0.1.11"
+VERSION = "0.1.12"
 
 setup(
     name="PyTrustNFe",