Moved py.code code over to py.test

Fix #103

_pytest/_code/_py2traceback.py

@@ -0,0 +1,79 @@
+# copied from python-2.7.3's traceback.py
+# CHANGES:
+# - some_str is replaced, trying to create unicode strings
+#
+import types
+
+def format_exception_only(etype, value):
+    """Format the exception part of a traceback.
+
+    The arguments are the exception type and value such as given by
+    sys.last_type and sys.last_value. The return value is a list of
+    strings, each ending in a newline.
+
+    Normally, the list contains a single string; however, for
+    SyntaxError exceptions, it contains several lines that (when
+    printed) display detailed information about where the syntax
+    error occurred.
+
+    The message indicating which exception occurred is always the last
+    string in the list.
+
+    """
+
+    # An instance should not have a meaningful value parameter, but
+    # sometimes does, particularly for string exceptions, such as
+    # >>> raise string1, string2  # deprecated
+    #
+    # Clear these out first because issubtype(string1, SyntaxError)
+    # would throw another exception and mask the original problem.
+    if (isinstance(etype, BaseException) or
+        isinstance(etype, types.InstanceType) or
+        etype is None or type(etype) is str):
+        return [_format_final_exc_line(etype, value)]
+
+    stype = etype.__name__
+
+    if not issubclass(etype, SyntaxError):
+        return [_format_final_exc_line(stype, value)]
+
+    # It was a syntax error; show exactly where the problem was found.
+    lines = []
+    try:
+        msg, (filename, lineno, offset, badline) = value.args
+    except Exception:
+        pass
+    else:
+        filename = filename or "<string>"
+        lines.append('  File "%s", line %d\n' % (filename, lineno))
+        if badline is not None:
+            lines.append('    %s\n' % badline.strip())
+            if offset is not None:
+                caretspace = badline.rstrip('\n')[:offset].lstrip()
+                # non-space whitespace (likes tabs) must be kept for alignment
+                caretspace = ((c.isspace() and c or ' ') for c in caretspace)
+                # only three spaces to account for offset1 == pos 0
+                lines.append('   %s^\n' % ''.join(caretspace))
+        value = msg
+
+    lines.append(_format_final_exc_line(stype, value))
+    return lines
+
+def _format_final_exc_line(etype, value):
+    """Return a list of a single line -- normal case for format_exception_only"""
+    valuestr = _some_str(value)
+    if value is None or not valuestr:
+        line = "%s\n" % etype
+    else:
+        line = "%s: %s\n" % (etype, valuestr)
+    return line
+
+def _some_str(value):
+    try:
+        return unicode(value)
+    except Exception:
+        try:
+            return str(value)
+        except Exception:
+            pass
+    return '<unprintable %s object>' % type(value).__name__