How to use pprint in Python?

Exploring the pprint library using explainations and examples.

pprint is used to print a beautified representation of an object in Python. It is available as a standard library that comes preinstalled with Python.

#more

This article will explore how pprint is used and what formatting options it provides.

1. pprint.pprint(object)¶

This is the most famous function from the pprint module.

pprint.pprint(object, stream=None, indent=1, width=80, depth=None, *, compact=False, sort_dicts=True, underscore_numbers=False)¶

It passes the arguments and keyword arguments to the PrettyPrinter class constructor. Following are the arguments accepted by the function:

• object: Python object to print
• indent: The amount of indentation to use in every new nesting level
• width: Maximum number of characters that can be printed in a line
• depth: Specifies the number of nesting levels to print, after the depth is surpassed ... characters are printed
• sort_dicts: If this is False, dictionaries will be displayed with their keys in insertion order, otherwise the dict keys will be sorted.
• underscore_numbers: Add _ separator to every thousandths place in a number
• compact: If true, adjust items of a sequence in the width else print each element in a new line
• stream: Stream to which data is to be sent like StringIO or BytesIO, defaults to sys.stdout

Example:

from pprint import pprint

data = [{"language": "Python", "application": ["Data Science", "Automation", "Scraping", "API"]}, {"language": "Javascript", "application": ["Web Development", "API", "Web Apps", "Games"]}]

pprint(data, indent=3)

Output:

[  {  'application': ['Data Science', 'Automation', 'Scraping', 'API'],
      'language': 'Python'},
   {  'application': ['Web Development', 'API', 'Web Apps', 'Games'],
      'language': 'Javascript'}]

Example with and without sort_dicts:

from pprint import pprint

values = {'a': 1, 'd': 4, 'b': 2}

pprint(values)
# {'a': 1, 'b': 2, 'd': 4}

pprint(values, sort_dicts=False)
# {'a': 1, 'd': 4, 'b': 2}

pprint.pformat(object)¶

pformat() is similar to pprint(), the distinctions are:

• pprint sends formatted data to a stream whereas pformat returns a string with formatted data
• pformat does not take stream argument, all other arguments remain as they were

Example:

from pprint import pformat

nested_dict = [{"language": "Python", "application": ["Data Science", "Automation", "Scraping", "API"]}, {"language": "Javascript", "application": ["Web Development", "API", "Web Apps", "Games"]}]

string_representation = pformat(nested_dict)
print(string_representation)

Output:

[{'application': ['Data Science', 'Automation', 'Scraping', 'API'],
  'language': 'Python'},
 {'application': ['Web Development', 'API', 'Web Apps', 'Games'],
  'language': 'Javascript'}]

pprint.pp(object)¶

Alias to pprint.pprint(), available from Python 3.8 and above.

pprint.isreadable(object)¶

Returns True if the object passed is readable by pprint, if an object is readable it can be pretty printed.

pprint.isrecursive(object)¶

Returns True if the object passed has recursive structure.

Example:

from pprint import pprint, isrecursive

recursive_dict = {}
recursive_dict[0] = recursive_dict[1] = recursive_dict

print(isrecursive(recursive_dict))
pprint(recursive_dict)

Output:

True
{0: <Recursion on dict with id=140056761037664>,
 1: <Recursion on dict with id=140056761037664>}