webargs

Homepage: https://webargs.readthedocs.io/

webargs is a Python library for parsing and validating HTTP request objects, with built-in support for popular web frameworks, including Flask, Django, Bottle, Tornado, Pyramid, Falcon, and aiohttp.

from flask import Flask
from webargs import fields
from webargs.flaskparser import use_args

app = Flask(__name__)


@app.route("/")
@use_args({"name": fields.Str(required=True)}, location="query")
def index(args):
    return "Hello " + args["name"]


if __name__ == "__main__":
    app.run()

# curl http://localhost:5000/\?name\='World'
# Hello World

Install

pip install -U webargs

Documentation

Full documentation is available at https://webargs.readthedocs.io/.

Support webargs

webargs is maintained by a group of volunteers. If you'd like to support the future of the project, please consider contributing to our Open Collective:

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Professional Support

Professionally-supported webargs is available through the Tidelift Subscription.

Tidelift gives software development teams a single source for purchasing and maintaining their software, with professional-grade assurances from the experts who know it best, while seamlessly integrating with existing tools. [Get professional support]

Security Contact Information

To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.

Project Links

• Docs: https://webargs.readthedocs.io/
• Changelog: https://webargs.readthedocs.io/en/latest/changelog.html
• Contributing Guidelines: https://webargs.readthedocs.io/en/latest/contributing.html
• PyPI: https://pypi.python.org/pypi/webargs
• Issues: https://github.com/marshmallow-code/webargs/issues
• Ecosystem / related packages: https://github.com/marshmallow-code/webargs/wiki/Ecosystem

License

MIT licensed. See the LICENSE file for more details.

Changelog

Unreleased

Bug fixes:

• Correct the package metadata for marshmallow versions which are supported by webargs

8.7.0 (2025-04-18)

Other changes:

• Test against Python 3.13 (982{.interpreted-text role=”pr”}).
• Drop support for Python 3.8, which is EOL (981{.interpreted-text role=”pr”}).
• Support marshmallow 4 (987{.interpreted-text role=”pr”}).

8.6.0 (2024-09-11)

Bug fixes:

• Fix the handling of invalid JSON bodies in the bottle parser to support bottle versions >=0.13 (974{.interpreted-text role=”pr”}).

Other changes:

• MultiDictProxy now inherits from MutableMapping rather than

  Mapping (960{.interpreted-text role=”pr”}).

8.5.0 (2024-04-25)

Other changes:

• Test against Python 3.12.
• Async location loading now supports loader functions which are not themselves async, but which return an awaitable result. This means that users who are already handling awaitable objects can return them from non-async loaders and expect webargs to await them. This allows some async interactions with supported frameworks, where the webargs-provided parser returns a framework object and the framework can be set to return awaitables, e.g., the Falcon parser. Thanks j0k2r{.interpreted-text role=”user”} for the PR! (935{.interpreted-text role=”pr”})

8.4.0 (2024-01-07)

Features:

• Add a new class attribute, empty_value to DelimitedList and DelimitedTuple, with a default of "". This controls the value deserialized when an empty string is seen.

empty_value can be used to handle types other than strings more gracefully, e.g.

from webargs import fields


class IntList(fields.DelimitedList):
    empty_value = 0


myfield = IntList(fields.Int())

::: note ::: title Note :::

empty_value will be changing in webargs v9.0 to be missing by default. This will allow use of fields with load_default to specify handling of the empty value. :::

• The rule for default argument names has been made configurable by overriding the get_default_arg_name method. This is described in the argument passing documentation.

Other changes:

• Drop support for Python 3.7, which is EOL.
• Type annotations for FlaskParser have been improved.

8.3.0 (2023-07-10)

Features:

• webargs.Parser now inherits from typing.Generic and is parametrizable over the type of the request object. Various framework-specific parsers are parametrized over their relevant request object classes.
• webargs.Parser and its subclasses now support passing arguments as a single keyword argument without expanding the parsed data into its

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