[Python-Dev] A type of out-of-range exception for %c

Serhiy Storchaka storchaka at gmail.com
Sun Jun 23 20:59:37 CEST 2013


Currently %c formatting raises OverflowError if an argument is out of range.

 >>> '%c' % 1114112
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
OverflowError: %c arg not in range(0x110000)
 >>> '{:c}'.format(1114112)
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
OverflowError: %c arg not in range(0x110000)

The same for PyUnicode_Format(), PyUnicode_FromFromat() and 
PyUnicode_FromFromatV() in C API.

But chr() raises ValueError.

 >>> chr(1114112)
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
ValueError: chr() arg not in range(0x110000)

And ValueError looks more suitable, because it is not really an overflow 
(limitation of the C language, or a C type). Can we change an exception 
type for %c formatting from OverflowError to ValueError?



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