Dan's solution is just wrong, and Ismail's in incomplete.
__str__()is not called,__repr__()is called.__repr__()should return a string, as pformat does.- print normally indents only 1 character and tries to save lines. If you are trying to figure out structure, set the width low and indent high.
Here is an example
class S:
def __repr__(self):
from pprint import pformat
return pformat(vars(self), indent=4, width=1)
a = S()
a.b = 'bee'
a.c = {'cats': ['blacky', 'tiger'], 'dogs': ['rex', 'king'] }
a.d = S()
a.d.more_c = a.c
print(a)
This prints
{ 'b': 'bee',
'c': { 'cats': [ 'blacky',
'tiger'],
'dogs': [ 'rex',
'king']},
'd': { 'more_c': { 'cats': [ 'blacky',
'tiger'],
'dogs': [ 'rex',
'king']}}}
Which is not perfect, but passable.
Answer from Charles Merriam on Stack OverflowPython
docs.python.org › 3 › library › pprint.html
pprint — Data pretty printer
The pprint module provides a capability to “pretty-print” arbitrary Python data structures in a form which can be used as input to the interpreter. If the formatted structures include objects which are not fundamental Python types, the ...
Analytics Vidhya
analyticsvidhya.com › home › how to use pprint in python? [explained with examples]
How to Use PPrint in Python? [Explained with Examples]
October 19, 2024 - The library contains just a single class, called pprint(). There are in total six parameters that can be used with this class.
python - How to use pprint to print an object using the built-in __str__(self) method? - Stack Overflow
I have a Python script which processes a .txt file which contains report usage information. I'd like to find a way to cleanly print the attributes of an object using pprint's pprint(vars(object)) function. The script reads the file and creates instances of a Report class. More on stackoverflow.com
Print dataclasses with indendation levels?
You can try prettyprint, but there is no way to tell without an example. https://docs.python.org/3/library/pprint.html More on reddit.com
7
1
January 23, 2024New Protocol for Pretty Printing
Looks pretty cool to me. dataclasses have this kind of repr thing built in, but it would be nice to have this tool if i were doing something else, to build them on my own. that said, your code above requires putting in the defaults twice. i bet you could automate the work inside __rich_repr__ by using inspect.signature, something like this: from inspect import signature from rich.repr import rich_repr @rich_repr class Bird: def __init__(self, name, eats=None, fly=True, extinct=False): self.name = name self.eats = list(eats) if eats else [] self.fly = fly self.extinct = extinct def __rich_repr__(self): for name, param in signature(Bird).parameters.items(): if param.default == param.empty: yield name, getattr(self, name) else: yield name, getattr(self, name), param.default if __name__ == "__main__": print(Bird("gull", eats=["fish", "chips", "ice cream", "sausage rolls"])) print(Bird("penguin", eats=["fish"], fly=False)) print(Bird("dodo", eats=["fruit"], fly=False, extinct=True)) More on reddit.com
2
66
June 11, 2021Made a color pretty printer which auto-generates a label before the value.
Check out https://github.com/samuelcolvin/python-devtools More on reddit.com
1
8
January 19, 2024Python Module of the Week
pymotw.com › 2 › pprint
pprint – Pretty-print data structures - Python Module of the Week
$ python pprint_pformat.py DEBUG Logging pformatted data DEBUG [(0, {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D', 'e': 'E', 'f': 'F', 'g': 'G', 'h': 'H'}), (1, {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D', 'e': 'E', 'f': 'F', 'g': 'G', 'h': 'H'}), (2, {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D', 'e': 'E', 'f': 'F', 'g': 'G', 'h': 'H'})] The PrettyPrinter class used by pprint() can also work with your own classes, if they define a __repr__() method.
Real Python
realpython.com › python-pretty-print
Prettify Your Data Structures With Pretty Print in Python – Real Python
March 18, 2026 - The output isn’t pretty when you use print() on large dictionaries or long lists—it’s efficient, but not pretty. The pprint module in Python is a utility module that you can use to print data structures in a readable, pretty way.
Jython
jython.org › jython-old-sites › docs › library › pprint.html
8.18. pprint — Data pretty printer — Jython v2.5.2 documentation
The pprint module provides a capability to “pretty-print” arbitrary Python data structures in a form which can be used as input to the interpreter. If the formatted structures include objects which are not fundamental Python types, the representation may not be loadable.
Top answer 1 of 6
40
Dan's solution is just wrong, and Ismail's in incomplete.
__str__()is not called,__repr__()is called.__repr__()should return a string, as pformat does.- print normally indents only 1 character and tries to save lines. If you are trying to figure out structure, set the width low and indent high.
Here is an example
class S:
def __repr__(self):
from pprint import pformat
return pformat(vars(self), indent=4, width=1)
a = S()
a.b = 'bee'
a.c = {'cats': ['blacky', 'tiger'], 'dogs': ['rex', 'king'] }
a.d = S()
a.d.more_c = a.c
print(a)
This prints
{ 'b': 'bee',
'c': { 'cats': [ 'blacky',
'tiger'],
'dogs': [ 'rex',
'king']},
'd': { 'more_c': { 'cats': [ 'blacky',
'tiger'],
'dogs': [ 'rex',
'king']}}}
Which is not perfect, but passable.
2 of 6
14
pprint.pprint doesn't return a string; it actually does the printing (by default to stdout, but you can specify an output stream). So when you write print record, record.__str__() gets called, which calls pprint, which returns None. str(None) is 'None', and that gets printed, which is why you see None.
You should use pprint.pformat instead. (Alternatively, you can pass a StringIO instance to pprint.)
W3Schools
w3schools.com › python › ref_module_pprint.asp
Python pprint Module
The pprint module formats Python objects in a way that's easier for humans to read.
Scaler
scaler.com › home › topics › python pprint module
Python Pprint Module - Scaler Topics
May 4, 2023 - Many arguments like width, depth, indent, etc can be used to specify the rules of formatting using the Python pprint(). A custom object can be created with the linting rules using the class PrettyPrinter.
Python
docs.python.org › 2 › library › pprint.html
8.18. pprint — Data pretty printer — Python 2.7.18 documentation
July 19, 2020 - The pprint module provides a capability to “pretty-print” arbitrary Python data structures in a form which can be used as input to the interpreter. If the formatted structures include objects which are not fundamental Python types, the representation may not be loadable.
Python Engineer
python-engineer.com › posts › pprint-python
How to use pprint in Python? - Python Engineer
May 17, 2022 - This is the most famous function from the pprint module. It passes the arguments and keyword arguments to the PrettyPrinter class constructor.
Read the Docs
stackless.readthedocs.io › en › 2.7-slp › library › pprint.html
8.18. pprint — Data pretty printer — Stackless-Python 2.7.15 documentation
>>> import pprint >>> stuff = ['spam', 'eggs', 'lumberjack', 'knights', 'ni'] >>> stuff.insert(0, stuff[:]) >>> pp = pprint.PrettyPrinter(indent=4) >>> pp.pprint(stuff) [ ['spam', 'eggs', 'lumberjack', 'knights', 'ni'], 'spam', 'eggs', 'lumberjack', 'knights', 'ni'] >>> tup = ('spam', ('eggs', ('lumberjack', ('knights', ('ni', ('dead', ... ('parrot', ('fresh fruit',)))))))) >>> pp = pprint.PrettyPrinter(depth=6) >>> pp.pprint(tup) ('spam', ('eggs', ('lumberjack', ('knights', ('ni', ('dead', (...))))))) The PrettyPrinter class supports several derivative functions:
DataFlair
data-flair.training › blogs › python-pprint
Python pprint Module - Python Data Pretty Printer - DataFlair
April 24, 2026 - So, let’s try printing this with pprint instead. ... So, what does Python pprint do? It formats an object and writes it to the data stream we pass to it as an argument.
seenode blog
seenode.com › blog › how-to-use-python-pretty-print-pprint
How to Use Python Pretty Print (pprint) for Cleaner Python Output | seenode blog
May 19, 2025 - For example, if you want to work with JSON data from an API, or parsing log files, or debug Python objects with lots of levels, pprint should be your first choice that will save time. Firstly, you need to import the pprint module. ... You can use the pprint() method or instantiate your pprint object with PrettyPrinter(). ... Now you can create a sample dictionary to show some of the arguments of the class pprint().
TutorialsPoint
tutorialspoint.com › python_text_processing › python_pretty_prints.htm
Python Text Processing - Pretty Printing
Those data objects can represent ... module and after applying it. import pprint student_dict = {'Name': 'Tusar', 'Class': 'XII', ......
GeeksforGeeks
geeksforgeeks.org › pprint-data-pretty-printer-python
pprint : Data pretty printer in Python - GeeksforGeeks
This article is about a pretty useful built-in module in Python, pprint. The pprint module provides a capability to “pretty-print” arbitrary Python data structures in a well-formatted and more readable way!
Published: October 6, 2023
Better Programming
betterprogramming.pub › how-to-pretty-print-in-python-9b1d8764d151
How To Pretty Print in Python. Start using the pprint library | by Jonathan Hsu | Better Programming
December 5, 2019 - Short for Pretty Printer, pprint is a native Python library that allows you to customize the formatting of your output. Refer to the official documentation for a full list of library and all properties available.
Note.nkmk.me
note.nkmk.me › home › python
Pretty-print in Python: pprint | note.nkmk.me
May 17, 2023 - s_normal = str(l) print(s_normal) # [{'Name': 'Alice XXX', 'Age': 40, 'Points': [80, 20]}, {'Name': 'Bob YYY', 'Age': 20, 'Points': [90, 10]}, {'Name': 'Charlie ZZZ', 'Age': 30, 'Points': [70, 30]}] print(type(s_normal)) # <class 'str'> ... You can use pprint.pformat() to get the output of pprint.pprint() as the string str.
Python
docs.python.org › 3.4 › library › pprint.html
8.11. pprint — Data pretty printer — Python 3.4.10 documentation
The pprint module provides a capability to “pretty-print” arbitrary Python data structures in a form which can be used as input to the interpreter. If the formatted structures include objects which are not fundamental Python types, the representation may not be loadable.
GitHub
github.com › python › cpython › blob › main › Lib › pprint.py
cpython/Lib/pprint.py at main · python/cpython
· Functions · --------- · pformat() Format a Python object into a pretty-printed representation. · pprint() Pretty-print a Python object to a stream [default is sys.stdout]. ·
Author: python
CodersLegacy
coderslegacy.com › home › python › python pprint (pretty print)
Python pprint (pretty print) - CodersLegacy
May 24, 2020 - The PrettyPrinter() function creates a instance (object) of the pprint class. The benefit of this is that we get to pass additional parameters to change how the data is printed. We’ll re-use the first example for this section.