update to python3.7

lib/python3.7/site-packages/cffi/error.py

@@ -0,0 +1,23 @@
+
+class FFIError(Exception):
+    pass
+
+class CDefError(Exception):
+    def __str__(self):
+        try:
+            current_decl = self.args[1]
+            filename = current_decl.coord.file
+            linenum = current_decl.coord.line
+            prefix = '%s:%d: ' % (filename, linenum)
+        except (AttributeError, TypeError, IndexError):
+            prefix = ''
+        return '%s%s' % (prefix, self.args[0])
+
+class VerificationError(Exception):
+    """ An error raised when verification fails
+    """
+
+class VerificationMissing(Exception):
+    """ An error raised when incomplete structures are passed into
+    cdef, but no verification has been done
+    """