[Python-Dev] PEP 553: Built-in debug() (original) (raw)

Nathaniel Smith njs at pobox.com
Tue Sep 5 22:58:46 EDT 2017

On Tue, Sep 5, 2017 at 6:14 PM, Barry Warsaw <barry at python.org> wrote:

I’ve written a PEP proposing the addition of a new built-in function called debug(). Adding this to your code would invoke a debugger through the hook function sys.debughook().

The 'import pdb; pdb.set_trace()' dance is extremely obscure, so replacing it with something more friendly seems like a great idea.

Maybe breakpoint() would be a better description of what set_trace() actually does? This would also avoid confusion with IPython's very useful debug magic: https://ipython.readthedocs.io/en/stable/interactive/magics.html#magic-debug and which might also be worth stealing for the builtin REPL. (Personally I use it way more often than set_trace().)

Example:

In [1]: def f(): ...: x = 1 ...: raise RuntimeError ...:

In [2]: f()

RuntimeError Traceback (most recent call last) in () ----> 1 f()

in f() 1 def f(): 2 x = 1 ----> 3 raise RuntimeError

RuntimeError:

In [3]: debug

(3)f() 1 def f(): 2 x = 1 ----> 3 raise RuntimeError

ipdb> p x 1

-n

-- Nathaniel J. Smith -- https://vorpus.org

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