Is there a Python equivalent to Perl's Data::Dumper?

Question

Is there a Python module that can be used in the same way as Perl's Data::Dumper module?

Edit: Sorry, I should have been clearer. I was mainly after a module for inspecting data rather than persisting.

BTW Thanks for the answers. This is one awesome site!

Answer 1

Possibly a couple of alternatives: pickle, marshal, shelve.

Answer 2

Data::Dumper has two main uses: data persistence and debugging/inspecting objects. As far as I know, there isn't anything that's going to work exactly the same as Data::Dumper.

I use pickle for data persistence.

I use pprint to visually inspect my objects / debug.

Answer 3

I think the closest you will find is the pprint module.

>>> l = [1, 2, 3, 4]
>>> l.append(l)
>>> d = {1: l, 2: 'this is a string'}
>>> print d
{1: [1, 2, 3, 4, [...]], 2: 'this is a string'}

>>> pprint.pprint(d)
{1: [1, 2, 3, 4, <Recursion on list with id=47898714920216>],
 2: 'this is a string'}

Answer 4

• For serialization, there are many options.

  • One of the best is JSON, which is a language-agnostic standard for serialization. It is available in 2.6 in the stdlib json module and before that with the same API in the third-party simplejson module.

  • You do not want to use marshal, which is fairly low-level. If you wanted what it provides, you would use pickle.

  • I avoid using pickle the format is Python-only and insecure. Deserializing using pickle can execute arbitrary code.

    • If you did use pickle, you want to use the C implementation thereof. (Do import cPickle as pickle.)

• For debugging, you usually want to look at the object's repr or to use the pprint module.