Motivation

Python's standard pretty print library (pprint) doesn't support user defined class. Once I wanted to print Python's AST prettier, however it's not possible to use "pprint" for the purpose.

What is it?

This library is an implementation in Python of "A prettier print" introduced by Philip Wadler.

http://homepages.inf.ed.ac.uk/wadler/papers/prettier/prettier.pdf

The algorithm was also implemented in Ruby's standard library: prettyprint.rb.

http://ruby-doc.org/stdlib/libdoc/prettyprint/rdoc/classes/PrettyPrint.html

Example

The purpose of this library is to give prettyprint ability on your class. In examples/show_ast.py you can see such examples. Here are small samples.

>>> from prettier import *
>>> docs = [Text("1. abc"), Text("2. abc"), Text("3. abc")]

# fill given space
>>> print(pretty(40, fill(docs)))
1. abc 2. abc 3. abc

>>> print(pretty(13, fill(docs)))
1. abc 2. abc
3. abc

>>> print(pretty(8, fill(docs)))
1. abc
2. abc
3. abc

# horizontal only
>>> print(pretty(1, spread(docs)))
1. abc 2. abc 3. abc

# vertical only
>>> print(pretty(100, stack(docs)))
1. abc
2. abc
3. abc

# when there isn't enough space to put horizontal, put vertical
>>> print(pretty(20, stack_or_spread(docs)))
1. abc 2. abc 3. abc

>>> print(pretty(13, stack_or_spread(docs)))
1. abc
2. abc
3. abc

# when there isn't enough space to put horizontal, use indent
>>> print(pretty(10, can_break_with_nest(docs)))
1. abc
  2. abc
  3. abc

Setup

$ easy_install prettier

Usage

Read the doctest please.

History

Roadmap

• Make a function pprint(obj) which work like standard pprint.pprint

When the goal is achived the version goes 1.0.

For developer(include me)

Here is the repository: https://bitbucket.org/nishio/prettierprint

Don't forget to run test and confirm tests cover all code:

$ coverage run prettier/__init__.py && coverage html

Don't forget to test README.rst is valid:

$ rst2html.py README.rst > README.html

When you relaese new version, don't put bdist option.:

$ python setup.py sdist bdist_egg upload

Lisence

Same as Python 3.0.

Acknowleagement

• Takayuki SHIMIZUKAWA <shimizukawa at gmail com>
• Atsushi Odagiri <aodagx at gmail com>
• yutaka matsubara <yutaka matsubara at gmail com>

Contact

NISHIO Hirokazu <nishio (dot) hirokazu (at) gmail (dot) com>