Question 1

How do I install python-magic on Windows?

Accepted Answer

First, download 64-bit libmagic DLLs from linked GitHub repos like file-windows, then install python-magic via pip. Ensure Python and libmagic builds match (32/64-bit) to avoid DLL errors, as noted in the troubleshooting section.

Question 2

Is python-magic better than Python's mimetypes module?

Accepted Answer

Yes, for accuracy; mimetypes relies on file extensions, while python-magic examines file headers via libmagic, making it more reliable for security validation and handling files with incorrect extensions, though it requires external dependencies.

Question 3

How can I get the MIME type of a file using python-magic?

Accepted Answer

Use magic.from_file('filename', mime=True) or create a Magic instance with mime=True. This returns the MIME type based on file content rather than extension, ideal for upload validation in web apps.

Question 4

Does python-magic work with compressed files like .gz?

Accepted Answer

Yes, set uncompress=True in the Magic class to automatically decompress and identify the contents. For example, magic.Magic(uncompress=True).from_file('test.gz') will return the uncompressed file type.

Question 5

What's the difference between from_file and from_buffer?

Accepted Answer

from_file reads from a file path, while from_buffer takes a bytes object; use from_buffer for in-memory data or to limit reads to the first N bytes (e.g., 2048 for accuracy), as recommended in the README to avoid misidentification.

Question 6

Is python-magic thread-safe for multi-threaded apps?

Accepted Answer

The basic functions might be, but the Magic class is not thread-safe and can fail if shared across threads. For concurrent use, create separate Magic instances per thread or avoid the class entirely for simple detection.

Question 7

How to handle errors when magic files are not found?

Accepted Answer

Specify the path explicitly with magic.Magic(magic_file='path_to_magic_file'), as some libmagic installations don't point correctly to the database. This is a common fix mentioned in the troubleshooting guide.

python-magic

What is python-magic?

Overview

Use Cases

Best For

Related Projects

Found a gem we're missing?

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions