Add __str__ and tests for the three AcceptLanguage classes.

Accept.__str__ returns a tidied up version of the header value, and
AcceptLanguageValidHeader.__str__ does the same.

NilAccept.__str__ returns ''; but given that the corresponding
Accept.__str__ returns a tidied up version of the header value,
returning '' would be misleading when the header is not empty, but
rather is not found in the request. We also need to return a different
value to indicate an invalid header, which cannot be parsed and tidied
up. So we instead remove the ambiguity with '<no header in request>' and
'<invalid header value>'.

1 files changed, 26 insertions, 0 deletions

diff --git a/src/webob/acceptparse.py b/src/webob/acceptparse.py
index c8f4172..5fa8f0d 100644
--- a/src/webob/acceptparse.py
+++ b/src/webob/acceptparse.py
@@ -459,6 +459,26 @@ class AcceptLanguageValidHeader(AcceptLanguage):
             self.header_value,
         )
 
+    def __str__(self):
+        """
+        Return a tidied up version of the header value.
+
+        e.g. If the ``header_value`` is ``', \t,de;q=0.000 \t, es;q=1.000, zh,
+        jp;q=0.210  ,'``, ``str(instance)`` returns ``'de;q=0, es, zh,
+        jp;q=0.21'``.
+
+        """
+        result = []
+        for range_, qvalue in self.parsed:
+            if qvalue == 1.0:
+                item = range_
+            elif qvalue == 0.0:
+                item = '{};q=0'.format(range_)
+            else:
+                item = '{};q={}'.format(range_, qvalue)
+            result.append(item)
+        return ', '.join(result)
+
     def _old_match(self, mask, item):
         """
         Return whether a language tag matches a language range.
@@ -1445,6 +1465,9 @@ class AcceptLanguageNoHeader(_AcceptLanguageInvalidOrNoHeader):
     def __repr__(self):
         return '{}()'.format(self.__class__.__name__)
 
+    def __str__(self):
+        return '<no header in request>'
+
 
 class AcceptLanguageInvalidHeader(_AcceptLanguageInvalidOrNoHeader):
     """
@@ -1479,6 +1502,9 @@ class AcceptLanguageInvalidHeader(_AcceptLanguageInvalidOrNoHeader):
             self.header_value,
         )
 
+    def __str__(self):
+        return '<invalid header value>'
+
 
 class MIMEAccept(Accept):
     """