I’m trying to get access to the user agent with Flask, but I either can’t find the documentation on it, or it doesn’t tell me.
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Answer
from flask import request request.headers.get('User-Agent')
You can also use the request.user_agent
object which contains the following attributes which are created based on the useragent string:
- platform (windows, linux, macos, etc.)
- browser (chrome, firefox, msie, etc.)
- version
- language
- string (
== request.headers.get('User-Agent')
)
Note: As of werkzeug 2.0, the parsed data of request.user_agent
has been deprecated; if you want to keep getting details you need to use a custom UserAgent
implementation and set it as user_agent_class
on a custom Request
subclass, which is set as request_class
on the Flask
instance (or a subclass).
Here’s an example implementation that uses ua-parser
:
from ua_parser import user_agent_parser from werkzeug.user_agent import UserAgent from werkzeug.utils import cached_property class ParsedUserAgent(UserAgent): @cached_property def _details(self): return user_agent_parser.Parse(self.string) @property def platform(self): return self._details['os']['family'] @property def browser(self): return self._details['user_agent']['family'] @property def version(self): return '.'.join( part for key in ('major', 'minor', 'patch') if (part := self._details['user_agent'][key]) is not None )