Thank you for your responses, it’s actually some syntax error and copy and paste errors.
I want to share that a mapping file is different from a metadata file.
I received my reads from the MRDNA facility and I preprocess the raw sequence reads with software that makes use of the mapping file. The mapping file was sent to me with the reads. When I used Keemei to validate the mapping file it differentiates the mapping file from the metadata file, in fact, I cannot edit the mapping file for the preprocessing or multiplexing of the reads, it must be in a specific format and the column number is specific and cannot be changed.
At the alpha and beta diversity stage when I need to use the metadata file, I realised the mapping file cannot be used as a metadata file, I have to format the mapping file and then validate it again with Keemei.
I do not know why this is so, but the process is complicated and may be tough for beginnings.
A mapping file is different from a metadata file, is that true?