3>0 is True
Jussi Piitulainen
jpiitula at ling.helsinki.fi
Wed Sep 15 14:47:04 CEST 2010
Yingjie Lan writes:
> I am not sure how to interprete this, in the interactive mode:
>
> >>> 3>0 is True
> False
> >>> (3>0) is True
> True
> >>> 3> (0 is True)
> True
>
> Why did I get the first 'False'? I'm a little confused.
It is interpreted as equivalent to this:
>>> 3 > 0 and 0 is True
False
>From the language reference at python.org (section 5.9 Comparisons):
expressions like a < b < c have the interpretation that is
conventional in mathematics
...
Comparisons can be chained arbitrarily, e.g., x < y <= z is
equivalent to x < y and y <= z, except that y is evaluated only
once (but in both cases z is not evaluated at all when x < y is
found to be false).
<URL:http://docs.python.org/reference/expressions.html#notin>
More information about the Python-list
mailing list