Why do I always get an exception raised in this __init__()?

[Larry Martell]

On Thu, Aug 31, 2023 at 3:19 PM Chris Green via Python-list
<python-list at python.org> wrote:
>
> I'm obviously doing something very silly here but at the moment I
> can't see what.
>
> Here's the code:-
>
>     #!/usr/bin/python3
>     #
>     #
>     # GPIO
>     #
>     import gpiod
>     #
>     #
>     # Simple wrapper class for gpiod to make set and clearing outputs
>     easier
>     #
>     class Gpiopin:
>
>         def __init__(self, pin):
>             #
>             #
>             # scan through the GPIO chips to find the line/pin we want
>             #
>             for c in ['gpiochip0', 'gpiochip1', 'gpiochip2', 'gpiochip3']:
>
>                 chip = gpiod.Chip(c)
>                 for l in range(32):
>                     line = chip.get_line(l)
>                     if pin in line.name():
>                         print("Found: ", line.name())
>                         return
>             else:
>                 raise ValueError("Can't find pin '" + pin + "'")
>
>         def print_name(self):
>             print (self.line.name())
>
>         def set(self):
>             self.line.set_value(1)
>
>         def clear(self):
>             self.line.set_value(0)
>
>
> This is by no means the final code, the print() in the __init__() is
> just a diagnostic for example. However I really can't understand why I
> see the following when I try it:-
>
>     >>> import ngp
>     >>> ngp.Gpiopin("P9_23")
>     Found:  P9_23
>     Traceback (most recent call last):
>       File "<stdin>", line 1, in <module>
>       File "/home/chris/.cfg/hosts/bbb/bin/ngp.py", line 24, in __init__
>         return
>     ValueError: Can't find pin 'P9_23'
>     >>>
>
> Does a return in __init__() not do what I think it does?
>
> How else could/should I do this?

Change the return to a break