gh-120254: Add a commands argument to pdb.set_trace

[gaogaotiantian]

• Issue: Add a commands argument to pdb.set_trace so the user can feed commands from source code #120254

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📚 Documentation preview 📚: https://cpython-previews--120255.org.readthedocs.build/

[picnixz]

Suggested change

	The *commands* argument, if given, would be a list of commands to execute
	when the debugger starts. It has similar effects to the :file:`.pdbrc` file.
	The *commands* argument, if given, is a list of commands to execute
	when the debugger starts. Those commands are executed after those
	optionally provided by the :file:`.pdbrc` file.

[gaogaotiantian]

Do you think two "those" is a little bit confusing here? How about These commands are executed after any commands optionally provided by the :file:.pdbrc file?

[Delengowski]

I agree the double "those" is confusing.

[picnixz]

Oups, you're right! I'm sorry I didn't reply to your question 3 weeks ago btw, but yes your suggestion is way better!

[picnixz]

Suggested change

	Added ``commands`` argument to :class:`pdb.Pdb` which allows user to send debugger commands in the source file.
	Added ``commands`` argument to :class:`pdb.Pdb` which allows users to send debugger commands in the source file.

[mcepl]

The phrase “similar effects” is kind of vague. I am not sure how to say it more precisely. Link to the .pdbrc documentation? Not sure.

[gaogaotiantian]

I moved this argument to set_trace() where it makes more sense. Partially due to the impact of #121451 - we won't create a Pdb instance every time we try to bring up a debugger.

[gaogaotiantian]

Hi @brandtbucher , could you take a look at this feature and see if it's reasonable to add?

[brandtbucher]

Thanks a lot for your patience.

Finally got a chance to play with it... I loved finding out that breakpoint(commands=[...]) works now! I think this is a great change.

[gaogaotiantian]

@brandtbucher do you think this needs a whatsnew entry?

[brandtbucher]

I think NEWS is probably good enough, but you can certainly add it to What's New if you feel it's something that you want to publicize more! Adding and removing stuff from that doc is pretty lightweight.

[gaogaotiantian]

I'll just merge this then!