Hello,

I would like to report that two error messages of the Python parser are
not consistent. Please take a look at this:


>>> a = "hello"

>>> a + 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot concatenate 'str' and 'int' objects

>>> 1 + a
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for +: 'int' and 'str'


When the order of the objects is changed, that should only change the
order of the 'str' and 'int' words in the message.

So if a+1, then
TypeError: cannot concatenate 'str' and 'int' objects

and if 1+a, then
TypeError: cannot concatenate 'int' and 'str' objects

For the case  a + 1  I recommend:
TypeError: can't concatenate 'str' and 'int' objects

And for the case  1 + a  I recommend:
TypeError: can't concatenate 'int' and 'str' objects


Consistency matters!

I don't see a problem here. You may be mislead by the assumption that
the error messages are generated by the parser, which they aren't --
they are generated at runtime by the objects you try to add.

The two types report their failure to do the operation differently --
strings are usually concatenated, so the first one makes sense for
strings, but ints have no such notion.