Object presentation with pprint

23 Jan, 2015

In my last post, I discovered that there are all sorts of awesome things you can do to format strings for presentation in a Python program. In this episode, I learn that it's possible to do the same thing with all Python objects using pprint!

Let's crack it open and get to some pretty-printing!

import pprint

pp = pprint.PrettyPrinter(indent=4, width=60)

Okay, I've implemented a PrettyPrinter object that expects to indent things at the four-space mark and each line can only be 60 characters long. Cool.

team = ['We', 'live', 'in', 'cities', 'you\'ll', 'never', 'see', 'on', 'screen', 'not', 'very', 'pretty', 'but', 'we', 'sure', 'know', 'how', 'to', 'run', 'things']

# yes, that is a list of words in the chorus of Lorde's "Team"

pp.pprint(team)

Okay, awesome. I now print everything on its own line with a slight indentation.

What happens if I throw a custom object at it?

class Dog:
	def __init__(self, name, owner):
		self.name = name
		self.owner = owner

my_dog = Dog('Rufus', 'Joe')

pp.pprint(my_dog) # <__main__.Dog instance at 0x1007ebc20>

Oh, that's disappointing. I was hoping I'd get a nifty way of doing this without having to define a custom repr() method on Dog. Ah well.

So pprint does some stuff awesome, and some stuff... not as awesome. Onward!