Fix Issue #906: Resolve Interval.in_words() incompatibility with Python native datetime.datetime.

[Eren-Acar]

Pull Request Check List

• Added tests for changed code.
• Updated documentation for changed code.

Closes #906

Description

This pull request fixes #906, where the Interval.in_words() method produced inconsistent output when using native Python datetime objects.

Solution

In calendars variable with native Python, delta attributes such as self._delta.hours are not calculated correctly. These kind of functions have been re-codded to use total_seconds() instead. Now, the Interval.in_words() function works correctly with Python’s native datetime.datetime.

Example

import pendulum
from datetime import datetime

start_time = datetime(2025, 7, 25, 19, 26, 34)
end_time = datetime(2025, 7, 29, 19, 26, 34)

interval = pendulum.interval(start_time, end_time)
print("Native datetime interval: \n")
print(interval.in_words())
print("Interval days", interval.days)
print("Interval hours", interval.hours)
print("Interval minutes", interval.minutes)
print("Interval In Days: ", interval.in_days())
print("Interval In Hours: ", interval.in_hours() / 24)


start_time = pendulum.datetime(2025, 7, 25, 19, 26, 34)
end_time = pendulum.datetime(2025, 7, 29, 19, 26, 34)

interval = pendulum.interval(start_time, end_time)
print("\nPendulum datetime interval:\n")
print(interval.in_words())
print("Interval days", interval.days)
print("Interval hours", interval.hours)
print("Interval minutes", interval.minutes)
print("Interval In Days: ", interval.in_days())
print("Interval In Hours: ", interval.in_hours() / 24)

Before PR's Edit:

After PR's Edit:

[codspeed-hq]

CodSpeed Performance Report

Merging #921 will not alter performance

_{Comparing Eren-Acar:master (1bb428a) with master (3382956)}

Summary

✅ 1 untouched

[ashb]

Why is self._delta not correct already?

At that least this needs unit tests please