User-Agents Library

2.2.0 · active · verified Thu Apr 09

The `user-agents` library is a simple Python library for identifying devices (phones, tablets, PCs) and their capabilities by parsing browser user agent strings. It wraps the `ua-parser` library and provides a more convenient object-oriented interface. The current version is 2.2.0, and releases are made periodically to incorporate updates from `ua-parser` and add minor features.

Warnings

breaking Version 2.2.0 and newer explicitly require `ua-parser >= 0.10.0`. If you have an older version of `ua-parser` pinned in your environment, upgrading `user-agents` might lead to dependency conflicts or installation failures.
Fix: Ensure your `ua-parser` dependency is updated to at least `0.10.0` or allow pip to upgrade it automatically (`pip install --upgrade user-agents`). Consider using a virtual environment to manage dependencies.
gotcha Parsing an empty or `None` user agent string does not raise an error. Instead, `parse('')` returns a `UserAgent` object where properties like `is_pc`, `is_mobile`, `browser.family`, `os.family`, etc., will default to `False`, `None`, or 'Other'/'Unknown' respectively. This might not be the expected behavior for users anticipating an error or `None`.
Fix: Always check the returned `UserAgent` object's properties (e.g., `user_agent.is_unknown` or `user_agent.device.family == 'Other'`) if you need to specifically handle empty or unidentifiable user agents. You may want to implement explicit checks for empty strings before calling `parse()` if an error is preferred.
gotcha The underlying user agent definitions are provided by the `ua-parser` library. For the most accurate and up-to-date parsing, it's crucial that `ua-parser` (and thus `user-agents`) is kept up-to-date. Outdated versions may incorrectly identify newer devices or browsers.
Fix: Regularly upgrade the `user-agents` package (`pip install --upgrade user-agents`) to ensure you have the latest `ua-parser` definitions available. The `user-agents` library's `install_requires` ensures a compatible `ua-parser` version is installed.

Install

pip install user-agents Install user-agents

Imports

parse
```
from user_agents import parse
```

Quickstart

This quickstart demonstrates how to parse different user agent strings using `user_agents.parse` and access various properties like device type, operating system, and browser information. It also shows how the library handles empty strings gracefully, returning an object with 'Other' or empty values.

from user_agents import parse

# Example user agent strings
user_agent_string_mobile = 'Mozilla/5.0 (Linux; Android 10; SM-G973F) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Mobile Safari/537.36'
user_agent_string_desktop = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'
user_agent_string_empty = ''

# Parse a mobile user agent
user_agent_mobile = parse(user_agent_string_mobile)
print(f"Mobile UA: {user_agent_mobile.is_mobile} (Mobile)")
print(f"Device: {user_agent_mobile.device.family}, OS: {user_agent_mobile.os.family} {user_agent_mobile.os.version_string}")
print(f"Browser: {user_agent_mobile.browser.family} {user_agent_mobile.browser.version_string}\n")

# Parse a desktop user agent
user_agent_desktop = parse(user_agent_string_desktop)
print(f"Desktop UA: {user_agent_desktop.is_pc} (PC)")
print(f"Device: {user_agent_desktop.device.family}, OS: {user_agent_desktop.os.family} {user_agent_desktop.os.version_string}")
print(f"Browser: {user_agent_desktop.browser.family} {user_agent_desktop.browser.version_string}\n")

# Parse an empty user agent
user_agent_empty = parse(user_agent_string_empty)
print(f"Empty UA is_pc: {user_agent_empty.is_pc}")
print(f"Empty UA device family: {user_agent_empty.device.family}")

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