Registry / serialization / backports-datetime-fromisoformat

backports-datetime-fromisoformat

library2.0.3pypypi✓ verified 25d ago

This library provides a backport of Python 3.11's extended `datetime.fromisoformat` functionality to older Python versions (prior to 3.11). It allows parsing a wider range of ISO 8601 formatted strings, including those with timezone offsets using colons and fractional seconds. The current version is 2.0.3, with releases occurring on an as-needed basis to address compatibility or new Python version changes.

serialization

pip install "backports-datetime-fromisoformat; python_version < '3.11'"

github ↗package ↗docs ↗changelog ↗

INSTALL

IMPORT

SIG · BACKPORTS-DATETIME

backports-datetime-fromisoformat

serializationpythonv2.0.3

Install

1.6s avg

Import

5ms

Disk

45MB

Pass rate

8/ 10

Env Coverage8 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v2.0.3 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

glibc

py 3.10

✓ —

✓ 1.5s

py 3.11

✓ —

✓ 1.55s

py 3.12

✓ —

✓ 1.4s

py 3.13

1/2 runs

py 3.9

✓ —

✓ 1.8s

45MB installed

● package 45MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

datetime.fromisoformat

✓ import datetime import backports.datetime_fromisoformat

✗ from backports.datetime_fromisoformat import fromisoformat

This library monkey-patches the built-in `datetime.datetime` and `datetime.date` objects. You must import `datetime` first, then `backports.datetime_fromisoformat` to apply the patch. It does not expose `fromisoformat` directly from its own namespace.

This example demonstrates how to use the backported `fromisoformat` method. By importing `backports.datetime_fromisoformat` after `datetime`, it monkey-patches the standard library's `datetime` objects to accept ISO 8601 strings that conform to Python 3.11's broader parsing capabilities, such as timezone offsets with colons.

import datetime import backports.datetime_fromisoformat # This string would fail on Python < 3.11 without the backport due to the colon in the timezone offset isodate_str = "2023-10-27T10:00:00.123456+05:30" try: dt_object = datetime.datetime.fromisoformat(isodate_str) print(f"Successfully parsed: {dt_object}") print(f"Type: {type(dt_object)}") except ValueError as e: print(f"Error parsing date: {e}")

Debug

Known issues

gotchaThis library relies on monkey-patching. The `datetime.fromisoformat` method will only be extended if `backports.datetime_fromisoformat` is imported *after* the `datetime` module.

fix

Always ensure `import datetime` appears before `import backports.datetime_fromisoformat` in your code.

affects: all

breakingVersion 2.0.0 changed the underlying logic for the backported `fromisoformat` methods. Prior to 2.0.0, it backported Python 3.7's logic; from 2.0.0 onwards, it backports Python 3.11's logic, supporting a wider range of ISO 8601 formats.

fix

Applications migrating from 1.x.x to 2.x.x should be aware that `fromisoformat` will now accept more varied ISO 8601 strings. This is generally an improvement, but verify if any strict parsing assumptions were made based on older 3.7 behavior.

affects: >=2.0.0 (compared to <2.0.0)

gotchaThis library is designed for Python versions older than 3.11. Installing and importing it on Python 3.11 or newer has no effect on `datetime.fromisoformat` and adds unnecessary overhead.

fix

Conditionally install the package using environment markers in your `pyproject.toml` or `requirements.txt`: `backports-datetime-fromisoformat; python_version < '3.11'`.

affects: all

Upgrade

Version history

2.0.3latest on PyPI · released Dec 28, 2024

Audit

Dependencies

No dependency data recorded yet.

Agent activity

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Resources

githubhttps://github.com/movermeyer/backports.datetime_fromisoformat ↗

packagehttps://pypi.org/project/backports-datetime-fromisoformat/ ↗

docshttps://github.com/movermeyer/backports.datetime_fromisoformat ↗

changeloghttps://github.com/movermeyer/backports.datetime_fromisoformat/CHANGELOG.md ↗