signal.signal() built-in function doesnt throws a ValueError exception in Windows when is called with a different signal than SIGABRT, SIGFPE, SIGILL, SIGINT, SIGSEGV, or SIGTERM, as it is written in the documentation.

https://docs.python.org/2/library/signal.html#signal.signal
https://docs.python.org/3/library/signal.html#signal.signal

It throws an AttributeError Exception

>>> import signal
>>> import sys
>>> sys.platform
'win32'
>>> signal.signal(signal.SIGPIPE, lambda signum, frame: sys.exit(1))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'SIGPIPE'
>>>

Regards