Hello, i just found some strange things going around, could you please tell me if this is desired:

>>> 3 + 4
7
>>> 3 +- 4
-1
>>> 3 +-+ 4
-1
>>> 3 +-+- 4
7
>>> 3 +-+-+ 4
7
>>> 3 +-+-+- 4
-1
>>> 3 +-+-+-+ 4
-1
>>> 3 +-+-+-+- 4
7

This was found in Python 2.4.4c1. And also another one:


>>> _
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
NameError: name '_' is not defined
>>> 3 == 3
True
>>> _
True
>>> 3 
3
>>> _
3


So what the hell is '_' something very strange indeed.

I also found these working on the following:

Python 2.5 (r25:51908, Oct  6 2006, 15:22:41) 
[GCC 4.1.2 20060928 (prerelease) (Ubuntu 4.1.1-13ubuntu4)] on linux2

Seems to be a common 'problem' ?

In your first example, all + and - except the first + are seen as unary operators and modify the 4.

In your second example: "_" is a convenience variable in the interactive interpreter and always bound to the
latest expression result. At startup, there is no such result.

Ok, claryfies something, but i don't think, that this should be valid syntax. Maybe it is not a real bug, but definitly a gotcha.