homepage

The current error messages for divisions by 0 of float and complex
object say "float/complex division", whereas for int and long is
"integer/long division by zero":
>>> 5/0
ZeroDivisionError: integer division or modulo by zero
>>> 5.0/0
ZeroDivisionError: float division
The attached patch adds "by zero" to the error messages of float and
complex in case of division, modulo or divmod by zero.
(Should I add tests to check the error message too?)

So if we're going to change the error messages, it would be nice if the 
new error messages were grammatical English. 'complex division by zero' 
is fine, but e.g. 'float modulo by zero' doesn't really make sense.
Actually I'd be fine with 'float division by zero' for this, since there's 
an implicit division involved in computing a remainder. Or perhaps 
something more verbose, like 'right-hand argument to modulo operation is 
zero'.

No, I don't think you should add tests for the error messages; there 
should already be tests for the type of error, and that's enough.

The patch is *almost* okay.
errno = 0;
 	div = c_quot(v->cval,w->cval); /* The raw divisor value. */
 	if (errno == EDOM) {
-		PyErr_SetString(PyExc_ZeroDivisionError, "complex remainder");
+		PyErr_SetString(PyExc_ZeroDivisionError, "complex modulo by zero");
 		return NULL;
It should be as expressed in the code above. In the patch, the fixed
string is "complex remainder by zero", but this is broken English. I
propose "complex modulo by zero". Please fix your patch and we're good.

Fixed in r78319 (trunk) and r78320 (py3k). I just fixed the 'division' and left the 'modulo' and 'divmod' alone.