FileReader.ext and FileReader.extension are dissimilar in function but too similar in name

[krzywon]

The file suffix and the file format are distinct concepts, with the reader able to handle a format different from the that suggested by the suffix. Future you will benefit from attribute names that clearly distinguish them.

From the code it looks like the extension attribute is the file format, assigned from the lowercase suffix. The doc string should say that it is the format.

self.extension and self.ext will cause confusion. I suggest renaming self.ext to indicate that is a set of valid file formats.

In the case where the format is different from the suffix you may need an additional parameter to the read call to specify the format.

Originally posted by @pkienzle in #37 (comment)