Merge pull request #2734 from RonnyPfannschmidt/simplify-string-safening

simplyfy ascii escaping by using backslashreplace error handling

Author: nicoddemus

_pytest/compat.py

@@ -7,6 +7,7 @@
 import types
 import re
 import functools
+import codecs
 
 import py
 
@@ -122,12 +123,24 @@ def isclass(object):
 
 
 if _PY3:
-    import codecs
     imap = map
     izip = zip
     STRING_TYPES = bytes, str
     UNICODE_TYPES = str,
 
+    if PY35:
+        def _bytes_to_ascii(val):
+            return val.decode('ascii', 'backslashreplace')
+    else:
+        def _bytes_to_ascii(val):
+            if val:
+                # source: http://goo.gl/bGsnwC
+                encoded_bytes, _ = codecs.escape_encode(val)
+                return encoded_bytes.decode('ascii')
+            else:
+                # empty bytes crashes codecs.escape_encode (#1087)
+                return ''
+
     def _ascii_escaped(val):
         """If val is pure ascii, returns it as a str().  Otherwise, escapes
         bytes objects into a sequence of escaped bytes:
@@ -147,13 +160,7 @@ def _ascii_escaped(val):
 
         """
         if isinstance(val, bytes):
-            if val:
-                # source: http://goo.gl/bGsnwC
-                encoded_bytes, _ = codecs.escape_encode(val)
-                return encoded_bytes.decode('ascii')
-            else:
-                # empty bytes crashes codecs.escape_encode (#1087)
-                return ''
+            return _bytes_to_ascii(val)
         else:
             return val.encode('unicode_escape').decode('ascii')
 else:

changelog/2734.trivial

@@ -0,0 +1 @@
+Internal refactor: simplify ascii string escaping by using the backslashreplace error handler in newer Python 3 versions.