Force file_type on read

[guysoft]

Hey,
So working with files ending with .txt that are actually .csv files.
This is in fact the standard in Example GTFS Feed which are used by google and governments.

So I need a way to read a file ending in .txt as a .csv.

I see here in the code that there is a use of file_type, but it would not work if there is a file_name already defined. Is this a bug or covering a use-case I don't know?
Can I PR something that uses force_file_type or something like that?

class FileSourceInfo(SourceInfo):
    """Plugin description for a file source"""
    def is_my_business(self, action, **keywords):
        status = SourceInfo.is_my_business(self, action, **keywords)
        if status:
            file_name = keywords.get("file_name", None)
            if file_name:
                if is_string(type(file_name)):
                    file_type = find_file_type_from_file_name(file_name,
                                                              action)
                else:
                    raise IOError("Wrong file name")
            else:
                file_type = keywords.get("file_type")

            status = self.can_i_handle(action, file_type)
        return status

[chfw]

I acknowledge that this is a valid constraint. for physical file, the only way to tell pyexcel about the file format is the file extension.

A change in pyexcel_io may be required to support this feature. You can submit a PR too. We can work on it together.