mautrix-python/mautrix/util/magic.py

46 lines
1.4 KiB
Python

# Copyright (c) 2022 Tulir Asokan
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
from __future__ import annotations
import functools
import magic
try:
_from_buffer = functools.partial(magic.from_buffer, mime=True)
_from_filename = functools.partial(magic.from_file, mime=True)
except AttributeError:
_from_buffer = lambda data: magic.detect_from_content(data).mime_type
_from_filename = lambda file: magic.detect_from_filename(file).mime_type
def mimetype(data: bytes | bytearray | str) -> str:
"""
Uses magic to determine the mimetype of a file on disk or in memory.
Supports both libmagic's Python bindings and the python-magic package.
Args:
data: The file data, either as in-memory bytes or a path to the file as a string.
Returns:
The mime type as a string.
"""
if isinstance(data, str):
return _from_filename(data)
elif isinstance(data, bytes):
return _from_buffer(data)
elif isinstance(data, bytearray):
# Magic doesn't like bytearrays directly, so just copy the first 1024 bytes for it.
return _from_buffer(bytes(data[:1024]))
else:
raise TypeError(
f"mimetype() argument must be a string or bytes, not {type(data).__name__!r}"
)
__all__ = ["mimetype"]