import mimesniff

res = mimesniff.what('sample.mp3')
print(res)
# audio/mpeg
with open('sample.mp3', 'rb') as fin:
    res = mimesniff.what(fin)
    print(res)
    # audio/mpeg

with open('sample.mp3', 'rb') as fin:
    header = fin.read(512)
    res = mimesniff.what(header)
    print(res)
    # audio/mpeg