Icecream – A little debugging library • Hacker News Board

Re: Icecream – A little debugging library

#11

Post by jamescostian » Fri, May 10, 2019, 2:11 PM UTC

purplezooey wrote: post #10

It makes sense. Debugging is often a rocky road and you have to be superman sometimes.

Agreed. Print statements are too vanilla; you need to lay down some moose tracks so you can retrace your steps once in a blue moon

Re: Icecream – A little debugging library

#12

Post by jamescostian » Fri, May 10, 2019, 2:13 PM UTC

fonix wrote: post #9

drcongo wrote: post #8

Earlier quoted context omitted.

I think it's a play on "I scream", something a lot of us can associate with debugging.

Ah, thanks for pointing that out!

In addition, in the README they reference it like "ic(x)", which sounds like "I see x", and goes very well with the output that sounds like "I see x equals 5"

Re: Icecream – A little debugging library

#13

Post by bow_ » Fri, May 10, 2019, 2:21 PM UTC

I used to do print debugging a lot. And then I tried using the `breakpoint()` call available since Python 3.7[1], and now I can't imagine doing any serious debugging without PDB (or any other debugger).

(I mentioned Python, since this is linking to the Python-flavor of Icecream).

Sure, there are still times when just calling print() is sufficient. But they are becoming less frequent. `print()` is only shorter than `breakpoint()` by just 5 - len(variable_name_to_print) characters after all.

I know `import pdb; pdb.set_trace()` was available before, though `breakpoint()` is just a lot simpler, among others for the reasons they mentioned in the PEP.

There is also the `--pdb` flag in pytest[2], that lets me jump into a PDB session upon test failure.

All of this makes me think, what are the cases where print-level debugging is the better option in Python, compared to using an actual debugger?

[1] https://www.python.org/dev/peps/pep-0553/

[2] https://docs.pytest.org/en/latest/usage.html#using-the-built...

Re: Icecream – A little debugging library

#14

Post by nubela » Fri, May 10, 2019, 2:21 PM UTC

Why do I feel like this is totally not necessary? If I am doing print() debugging, it is because I am lazy. If I want real debugging, there are better tools.

Also, print() works just fine.

Re: Icecream – A little debugging library

#15

Post by cknd » Fri, May 10, 2019, 2:40 PM UTC

Two recent discussions about related-though-not-identical Python debugging tools:

https://news.ycombinator.com/item?id=19717786

https://news.ycombinator.com/item?id=19772902

Re: Icecream – A little debugging library

#16

Post by herge » Fri, May 10, 2019, 3:11 PM UTC

bow_ wrote: post #13

I used to do print debugging a lot. And then I tried using the `breakpoint()` call available since Python 3.7[1], and now I can't imagine doing any serious debugging without PDB (or any other debugger). (I mentioned Python, since this is linking to the Python-flavor of Icecream). Sure, there are still times when just calling print() is sufficient. But they are becoming less frequent. `print()` is only shorter than `b…

And if you really spend a lot of time in a python debugger, pudb (https://pypi.org/project/pudb/) is a lot of fun. It includes a full curses debugger, it saves breakpoints between runs, can run any interpreter (ipython, bpython, ...) you want, etc.

And since it's console only, you can even run it remotely without too much hassle.

Re: Icecream – A little debugging library

#17

Post by reikonomusha » Fri, May 10, 2019, 4:31 PM UTC

    (defmacro ic (expr)
      `(prog2
         (format t "~&ic| ~A: " ',expr)
         (prin1 ,expr)
         (terpri)))

This is a lisp macro that (1) ensures the debug statement is printed on a newline, (2) prints the expression that got evaluated in its originally read form, (3) prints the value readably, (4) prints a newline, (5) return EXPR. Conforms to ANSI Common Lisp. Works on all implementations. No cute logo or testing required.

If you want to inspect execution, interrupt it, resume it, look at the call stack, look at local variables, then you can use Lisp’s function called break. No external tool required. No installing a dependency or debugger. Works on all implementations.

    (break "stop right there!")

Re: Icecream – A little debugging library

#18

Post by gruns » Fri, May 10, 2019, 5:30 PM UTC

reikonomusha wrote: post #17

(defmacro ic (expr) `(prog2 (format t "~&ic| ~A: " ',expr) (prin1 ,expr) (terpri))) This is a lisp macro that (1) ensures the debug statement is printed on a newline, (2) prints the expression that got evaluated in its originally read form, (3) prints the value readably, (4) prints a newline, (5) return EXPR. Conforms to ANSI Common Lisp. Works on all implementations. No cute logo or testing required. If you want to…

Cute.

As you can see from IceCream's source, a little more hackery is required to get things working smoothly in Python. =]

Re: Icecream – A little debugging library

#19

Post by gruns » Fri, May 10, 2019, 5:31 PM UTC

jamescostian wrote: post #12

fonix wrote: post #9

Earlier quoted context omitted.

Ah, thanks for pointing that out!

In addition, in the README they reference it like "ic(x)", which sounds like "I see x", and goes very well with the output that sounds like "I see x equals 5"

Bingo. This was the original intention.

"I see [X].", et cetera.

Re: Icecream – A little debugging library

#20

Post by StavrosK » Fri, May 10, 2019, 6:41 PM UTC

bow_ wrote: post #13

I used to do print debugging a lot. And then I tried using the `breakpoint()` call available since Python 3.7[1], and now I can't imagine doing any serious debugging without PDB (or any other debugger). (I mentioned Python, since this is linking to the Python-flavor of Icecream). Sure, there are still times when just calling print() is sufficient. But they are becoming less frequent. `print()` is only shorter than `b…

If you're at a tty, PuDB is the best. For everything else, there's icecream.