Inaccuracy in checking file extension.

[singhpratyush]

Sometimes file extensions are not correct w.r.t. what they actually are. Moreover some files are not even provided with any format.

Using something similar to file command in linux would produce better results.
Maybe python-magic can help.

[jyn514]

Can you give an example of something classified wrong? It would be nice to classify based on file instead of file extensions, but that's a lower priority than bug fixes.