time.sleep error message misleading

[JustinFay]

BPO	37086
Nosy	@ericvsmith, @csabella, @Windsooon
PRs	bpo-37086: fixed time.sleep error message #13768

^{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 = None
created_at = <Date 2019-05-29.10:37:02.861>
labels = []
title = 'time.sleep error message misleading'
updated_at = <Date 2019-06-03.03:43:22.478>
user = 'https://bugs.python.org/JustinFay'

bugs.python.org fields:

activity = <Date 2019-06-03.03:43:22.478>
actor = 'Windson Yang'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = []
creation = <Date 2019-05-29.10:37:02.861>
creator = 'Justin Fay'
dependencies = []
files = []
hgrepos = []
issue_num = 37086
keywords = ['patch']
message_count = 6.0
messages = ['343880', '343894', '343904', '343909', '343958', '344374']
nosy_count = 4.0
nosy_names = ['eric.smith', 'cheryl.sabella', 'Windson Yang', 'Justin Fay']
pr_nums = ['13768']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue37086'
versions = ['Python 3.6']

Linked PRs

• gh-81267: Correct time.sleep error message #131055

[JustinFay]

Using python3.6 and calling time.sleep with an invalid argument the TypeError raised has the error message "TypeError: an integer is required". This is not the case as a float or integer is acceptable. Using python 2.7 the error message given is better "TypeError: a float is required".

[mangrisano]

The doc (3.7) says that the argument "may be a floating point number to indicate a more precise sleep time."
I think that TypeError message is right because you can choose how much precision you need but it's optional.
What do you think about that?

[ericvsmith]

I think it's reasonable to change the TypeError to say integer or float. That's what _PyTime_FromObject is looking for.

[csabella]

While not exactly the same, bpo-35707 is also about time.sleep and floats.

[JustinFay]

From looking at the code for this (note I am not a C programmer so may have gotten this wrong) _PyTime_FromObject first checks if the object is a float using PyFloat_Check(obj) this is evident as passing nan to time.sleep raises a ValueError with the message "Invalid value NaN (not a number)". However if the object is not a float it next assumes the only valid value to be an integer, this logic appears fine to me. The problem however is if the object is not an integer the code raises the error with the message that an integer is required, it is unaware that a before this branch of the code executes a float would have been an accepted value. In python I imagine the fix for this would be along the lines

try:
float(obj)
except (TypeError, ValueError):
try:
int(obj):
except (TypeError, ValueError):
raise TypeError('an float or integer is required')

[Windsooon]

I just create a PR for it.