Duration division, multiplication and mod broken for month lengths.

I am on the latest Pendulum version.
I have searched the issues of this repo and believe that this is not a duplicate.

OS Version: Windows 11
Pendulum version: 3.0.0

Issue

When doing math on Duration objects, months are ignored. This is because it uses the _to_microseconds method which ignores the months attribute.
https://github.com/sdispater/pendulum/blob/3e3fec6a5b66759078c5ae39c736ca95b78adbef/src/pendulum/duration.py#L356-L357
e.g. :

>>> pendulum.Duration(years=1)/pendulum.Duration(months=1)
Traceback (most recent call last):
  File "C:\Program Files\JetBrains\PyCharm 2022.2.2\plugins\python\helpers\pydev\pydevconsole.py", line 364, in runcode
    coro = func()
  File "<input>", line 1, in <module>
  File "C:\Users\chase\PycharmProjects\Flexget\py310\lib\site-packages\pendulum\duration.py", line 419, in __truediv__
    float, usec / other._to_microseconds()  # type: ignore[attr-defined]
ZeroDivisionError: division by zero

>>> pendulum.Duration(months=1)*3.0
Duration()

@sdispater

Duration only supports full months and years, hence floating-point multiplication is not supported.

@sdispater @Secrus I see two options here:

Raise an error when floating-point multiplication is applied on a Duration with years>0 and/or months>0.
Round up or down to the nearest integer as is done with __truediv__ https://github.com/sdispater/pendulum/blob/3e3fec6a5b66759078c5ae39c736ca95b78adbef/src/pendulum/duration.py#L431-L439

It should be relatively straight forward to defer to .total_seconds() since this already makes use of the years and months attributes correctly. I do agree that the number of microseconds (or seconds) in a month or year is ambiguous however pendulum already hardcodes these to be month=30days, year=365days. So given that, it should be possible to divide months by months, for example.

Navigation Menu

Repository navigation

Duration division, multiplication and mod broken for month lengths. #799

Issue

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Duration division, multiplication and mod broken for month lengths. #799

Description

Issue

Activity

Benji19967 commented on Mar 8, 2024

ruaridhw commented on Apr 14, 2025

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions