overwrite method

[ratel223]

Hi,

The Arcade game library has a UIMessageBox GUI widget class with an empty on_action method. They recommend overwriting that method using a syntax I do not know how to translate to Hy.

box = UIMessageBox(...)
@box.event("on_action")
def on_action(event: UIOnActionEvent):
    pass

The Arcade documentation is here.

Here is my code for the previous version of Arcade (I recently upgraded); it has a callback parameter. I now have to remove the callback parameter and overwrite the on_action method.

    (setv selection_msgbox (arcade.gui.UIMessageBox
      :width 240
      :height 130
      :message_text "Hi! Who will be playing with James today?"
      :callback self.on_selection_msgbox_close
      :buttons ["Daddy" "Mommy"]))

How can I do this in Hy?

Thank you.

[Kodiologist]

Have you tried py2hy?

[ratel223]

Excellent! I knew about hy2py, but not py2hy. Oh! It's eight years old and blows-up on build. Almost every source recommends creating a sub-class; I am not convinced that is the best way to handle this. The previous version of UIMessageBox has a callback argument; that's all I want. I found only one discussion <https://stackoverflow.com/questions/394770/override-a-method-at-instance-level> with an answer providing a way to replace a method of an instance; see Harshal Dhumal's answer. Here is a working example. import types class Dog: def bark(self): print("Woof") def new_bark(self): print("Woof Woof") fido = Dog() fido.bark() # replace bark with new_bark for this object only fido.bark = types.MethodType(new_bark, fido) fido.bark() # make sure I replaced the method on the one instance print("try a new dog") bingo = Dog() bingo.bark() Here is the output. Woof Woof Woof try a new dog Woof My code is now working ... well, this part is OK - there are other problems :-) (setv selection_msgbox (arcade.gui.UIMessageBox :width 240 :height 130 :message_text "Hi! Who will be playing with James today?" :buttons ["Daddy" "Mommy"])) ; replace the on_action method ; (setv selection_msgbox.on_action (types.MethodType on_selection_msgbox_close selection_msgbox))

…

On Sun, Jun 22, 2025 at 7:46 AM Kodi Arfer ***@***.***> wrote: Have you tried py2hy? — Reply to this email directly, view it on GitHub <#2665 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BFGIHCHC2IPMZQ3A4SHSMNT3E2JRXAVCNFSM6AAAAAB72YIRV6VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGNJUGIZDIOA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Claude Marinier

[Kodiologist]

[py2hy is] eight years old and blows-up on build.

Wrong one. Try the one on PyPI.

[ratel223]

Got it, thanks. Oh! It wants a really old version of Hy. py2hyb 0.9.5 requires hy==0.18.0, but you have hy 1.1.0 which is incompatible. It could still be useful: I could downgrade Hy, use py2hy, and upgrade Hy. I'm OK for now since I found an another approach which is easily translated to Hy.

…

On Sun, Jun 22, 2025 at 8:12 PM Kodi Arfer ***@***.***> wrote: [py2hy is] eight years old and blows-up on build. Wrong one. Try the one on PyPI. — Reply to this email directly, view it on GitHub <#2665 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BFGIHCBL25D4ULSX7ICEGF33E5A63AVCNFSM6AAAAAB72YIRV6VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGNJUGUZTQOI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Claude Marinier

[Kodiologist]

You did not get it. That's still the wrong one. Try the one on PyPI.

[ratel223]

I trusted the result of a Google search for py2hy; it pointed me to py2hyb on PyPI. That was my mistake. This time I searched directly on PyPI and it found py2hy-0.2.0 which was released on 5 June 2025. That looks much better. It's the correct one, right? I installed it with pip without error. I am using Hy 1.1.0 and Python 3.13.3 with pip 25.1.1 on Debian 12. I then tried to translate the example program from earlier in the conversation. It produced two exceptions. So I tried it with a simpler program. $ cat timestamp.py import datetime print( datetime.datetime.now().strftime("%Y%m%d-%H%M%S") ) This produced the same two exceptions as the other program; I checked with diff. $ py2hy timestamp.py Traceback (most recent call last): File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/macros.py", line 65, in import parse_tree = pattern.parse(args) File "/home/claude/Python-venv/lib/python3.13/site-packages/funcparserlib/parser.py", line 221, in parse (tree, _) = self.run(tokens, State(0, 0, None)) ~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/home/claude/Python-venv/lib/python3.13/site-packages/funcparserlib/parser.py", line 383, in _shift (v, s2) = self.run(tokens, s) ~~~~~~~~^^^^^^^^^^^ File "/home/claude/Python-venv/lib/python3.13/site-packages/funcparserlib/parser.py", line 306, in _add (v2, s3) = other.run(tokens, s2) ~~~~~~~~~^^^^^^^^^^^^ File "/home/claude/Python-venv/lib/python3.13/site-packages/funcparserlib/parser.py", line 534, in finished raise NoParseError("got unexpected token", s2) funcparserlib.parser.NoParseError: got unexpected token: hy.models.List([ hy.models.Expression([ hy.models.Symbol('.'), hy.models.Symbol('hy'), hy.models.Symbol('contrib'), hy.models.Symbol('hy-repr')]), hy.models.List([ hy.models.Symbol('hy-repr')])]), expected: end of input During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/home/claude/Python-venv/bin/py2hy", line 5, in <module> from py2hyb.py2hy import main File "<frozen importlib._bootstrap>", line 1360, in _find_and_load File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 935, in _load_unlocked File "<frozen importlib._bootstrap_external>", line 1022, in exec_module File "<frozen importlib._bootstrap_external>", line 1160, in get_code File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/importer.py", line 123, in _hy_source_to_code data = hy_compile(hy_tree, module) File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 882, in hy_compile result = compiler.compile(tree) File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 420, in compile raise e File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 411, in compile ret = self.compile_atom(tree) File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 405, in compile_atom return Result() + _model_compilers[type(atom)](self, atom) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^ File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 494, in _compile_branch last = self.compile(node) File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 420, in compile raise e File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 411, in compile ret = self.compile_atom(tree) File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 405, in compile_atom return Result() + _model_compilers[type(atom)](self, atom) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^ File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/compiler.py", line 566, in compile_expression expr = macroexpand(expr, self.module, self) File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/macros.py", line 401, in macroexpand obj = m( # If the macro's first parameter is named ...<4 lines>... else []), *map(as_model, tree[1:])) File "/home/claude/Python-venv/lib/python3.13/site-packages/hy/macros.py", line 67, in import raise _hy_compiler._syntax_error( ...<4 lines>... ) File "/home/claude/Python-venv/lib/python3.13/site-packages/py2hyb/py2hy.hy", line 10 (import [hy.contrib.hy-repr [hy-repr]]) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ hy.errors.HySyntaxError: parse error for pattern macro 'import': got unexpected token: hy.models.List([ hy.models.Expression([ hy.models.Symbol('.'), hy.models.Symbol('hy'), hy.models.Symbol('contrib'), hy.models.Symbol('hy-repr')]), hy.models.List([ hy.models.Symbol('hy-repr')])]), expected: end of macro call I have no idea what I am doing wrong.

…

On Sun, Jun 22, 2025 at 10:02 PM Kodi Arfer ***@***.***> wrote: You did not get it. That's still the wrong one. Try the one on PyPI. — Reply to this email directly, view it on GitHub <#2665 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BFGIHCGX2GV46ZPDDY7E2YL3E5N2VAVCNFSM6AAAAAB72YIRV6VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGNJUGU4DSNI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Claude Marinier

[Kodiologist]

You installed the right package, but you're probably still running the wrong one, since py2hy doesn't install a binary named py2hy. It's executed as python3 -m py2hy mycode.py. See the README.

[ratel223]

Hi Kodi, Yes, there was an old binary. I apologize for all my blunders. I learned a lot: there are sometimes a few packages with similar names and do not assume a package will run as a command. I already know to check the README, but I failed to do so in this case. This will be useful as I learn more about Hy. Thank you for your efforts in developing py2hy and your patience with me.

…

On Mon, Jun 23, 2025 at 1:13 PM Kodi Arfer ***@***.***> wrote: You installed the right package, but you're probably still running the wrong one, since py2hy doesn't install a binary named py2hy. It's executed as python3 -m py2hy mycode.py. See the README. — Reply to this email directly, view it on GitHub <#2665 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BFGIHCFIRWT7TTYR7WUROIT3FAYU7AVCNFSM6AAAAAB72YIRV6VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGNJVGM3DGMI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Claude Marinier

[Kodiologist]

You're welcome. It's unfortunate that there's at least two other unmaintained attempts at a Python-to-Hy translator floating around out there.