Question

How can I tell if a file is binary (non-text) in Python?

I am searching through a large set of files in Python, and keep getting matches in binary files. This makes the output look incredibly messy.

I know I could use grep -I, but I am doing more with the data than what grep allows for.

In the past, I would have just searched for characters greater than 0x7f, but utf8 and the like, make that impossible on modern systems. Ideally, the solution would be fast.

Answer 1

You can also use the mimetypes module:

import mimetypes
...
mime = mimetypes.guess_type(file)

It’s fairly easy to compile a list of binary mime types. For example Apache distributes with a mime.types file that you could parse into a set of lists, binary and text and then check to see if the mime is in your text or binary list.