[Python-Dev] displayhook behavior in pdb (original) (raw)

Paul Moore p.f.moore at gmail.com
Wed Sep 16 12:48:52 CEST 2009

2009/9/16 Michael Foord <fuzzyman at voidspace.org.uk>:

Georg Brandl wrote:

May I have a short vote on this issue: http://bugs.python.org/issue6903 In short, pdb (since 2.6) uses a separate displayhook in order to avoid being reassigned (which screws up debugging apps that use as gettext). In that displayhook, I did not add the suppression of printing None, as it can be confusing to look at variables and get no output: (Pdb) foo 1 (Pdb) bar (Pdb) (You could argue that this is what the "p" command is for though.) Now in Python 3, where print is a function, if you call print in a loop (e.g. to debug a list or dictionary, as it is advertised in the pdb docs under the "alias" command), the output has the printed values interspersed with "None"s. Now, what is the lesser evil?

IMO not showing the extraneous Nones is preferable.

I agree (although I don't use pdb, so my view shouldn't be given too much weight...) Paul.

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