pprint dictionary on multiple lines

Question:

I’m trying to get a pretty print of a dictionary, but I’m having no luck:

>>> import pprint
>>> a = {'first': 123, 'second': 456, 'third': {1:1, 2:2}}
>>> pprint.pprint(a)
{'first': 123, 'second': 456, 'third': {1: 1, 2: 2}}

I wanted the output to be on multiple lines, something like this:

{'first': 123,
 'second': 456,
 'third': {1: 1,
           2: 2}
}

Can pprint do this? If not, then which module does it? I’m using Python 2.7.3.

Asked By: mulllhausen

||

Answers:

Use width=1 or width=-1:

In [33]: pprint.pprint(a, width=1)
{'first': 123,
 'second': 456,
 'third': {1: 1,
           2: 2}}
Answered By: Warren Weckesser

If you are trying to pretty print the environment variables, use:

pprint.pprint(dict(os.environ), width=1)
Answered By: UngodlySpoon

You could convert the dict to json through json.dumps(d, indent=4)

import json

print(json.dumps(item, indent=4))
{
    "second": 456,
    "third": {
        "1": 1,
        "2": 2
    },
    "first": 123
}
Answered By: Ryan Chou

Two things to add on top of Ryan Chou’s already very helpful answer:

  • pass the sort_keys argument for an easier visual grok on your dict, esp. if you’re working with pre-3.6 Python (in which dictionaries are unordered)
print(json.dumps(item, indent=4, sort_keys=True))
"""
{
    "first": 123,
    "second": 456,
    "third": {
        "1": 1,
        "2": 2
    }
}
"""
  • dumps() will only work if the dictionary keys are primitives (strings, int, etc.)
Answered By: Zach Valenta

This is a Copy-Pasta for testing purposes and to help with a usage example.

from pprint import pprint  # I usually only need this module from the package. 

a = {'first': 123, 'second': 456, 'third': {1:1, 2:2}, 'zfourth': [{3:9, 7:8}, 'distribution'], 1:2344, 2:359832, 3:49738428, 4:'fourth', 5:{'dictionary':'of things', 'new':['l','i','s','t']}}

pprint(dict(a), indent=4, width=1)

# Wrap your variable in dict() function
# Optional: indent=4. for readability
# Required: width=1 for wrapping each item to its own row.
# Note: Default pprint is to sort the dictionary
# Note: This also auto-wraps anything sting that has spaces in it.  See 'of things' below.

# Documentation:  https://docs.python.org/3/library/pprint.html
# Examples:       https://pymotw.com/2/pprint/
# Blog:           https://realpython.com/python-pretty-print/

Provides the following result:

{   1: 2344,
    2: 359832,
    3: 49738428,
    4: 'fourth',
    5: {   'dictionary': 'of '
                         'things',
           'new': [   'l',
                      'i',
                      's',
                      't']},
    'first': 123,
    'second': 456,
    'third': {   1: 1,
                 2: 2},
    'zfourth': [   {   3: 9,
                       7: 8},
                   'distribution']}
Answered By: JayRizzo