Unexpected Behaviour of pprint.pprint

[gavindsouza]

BPO	36705
Nosy	@freddrake, @ericvsmith, @gavindsouza

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2019-04-23.13:26:24.995>
created_at = <Date 2019-04-23.12:47:49.735>
labels = ['3.7', 'type-bug', 'library']
title = 'Unexpected Behaviour of pprint.pprint'
updated_at = <Date 2019-04-23.13:26:24.990>
user = 'https://github.com/gavindsouza'

bugs.python.org fields:

activity = <Date 2019-04-23.13:26:24.990>
actor = 'fdrake'
assignee = 'none'
closed = True
closed_date = <Date 2019-04-23.13:26:24.995>
closer = 'fdrake'
components = ['Library (Lib)']
creation = <Date 2019-04-23.12:47:49.735>
creator = 'gavin'
dependencies = []
files = []
hgrepos = []
issue_num = 36705
keywords = []
message_count = 4.0
messages = ['340720', '340721', '340723', '340725']
nosy_count = 3.0
nosy_names = ['fdrake', 'eric.smith', 'gavin']
pr_nums = []
priority = 'normal'
resolution = 'rejected'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue36705'
versions = ['Python 3.7']

[gavindsouza]

For a simple string input, pprint would be expected to return an output similar to print. However, the functionality differs

### Code:
import time
from pprint import pprint

start = time.time()
time.sleep(0.5)
object_made = time.time()
time.sleep(0.5)
done = time.time()
time.sleep(0.5)
shown = time.time()

pprint(
    f"Time to create object: {object_made - start}s\n" +
    f"Time to insert 100000 rows: {done - object_made}s\n" +
    f"Time to retrieve 100000 rows: {shown - done}s\n"
)

### Output Received:
('Time to create object: 0.5010814666748047s\n'
'Time to insert 100000 rows: 0.5010972023010254s\n'
'Time to retrieve 100000 rows: 0.501101016998291s\n')

### Expected Output:
Time to create object: 0.5010814666748047s
Time to insert 100000 rows: 0.5010972023010254s
Time to retrieve 100000 rows: 0.501101016998291s

[gavindsouza]

if pprint is called without parameters, it returns a TypeError

>>> pprint()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: pprint() missing 1 required positional argument: 'object'

it would be beneficial however to return an empty string or a new line character instead. An erroneous call would generate an unnecessary run-time error in a huge script

[ericvsmith]

pprint.pprint is not designed to be a drop-in replacement for print. At this point, we cannot break existing code to change how pprint works.

I suggest you make a pprint.pprint wrapper that does what you want, or maybe subclass pprint.PrettyPrinter.

[freddrake]

Eric nailed it; pprint was not designed as a replacement for print, and was never intended to serve that purpose.

Rejecting as out of scope.