utility_scripts/process_vep_tsv.py: When purely giving output filename, an error is thrown instead of file being written in current directory.

[svandenhoek]

When purely using the filename as output without giving a relative/absolute path, an NotADirectoryError: Output file has to be placed in an directory that already exists! error is given:

$ python3 ./utility_scripts/process_vep_tsv.py -i ../output/train_input_annotated.tsv.gz -o train_input_test.tsv.gz 
Parsing CLI

Validating input arguments.
Traceback (most recent call last):
  File "/path/to/capice-resources-main/./utility_scripts/process_vep_tsv.py", line 178, in <module>
    main()
  File "/path/to/capice-resources-main/./utility_scripts/process_vep_tsv.py", line 104, in main
    validator.validate_output_cla(output)
  File "/path/to/capice-resources-main/./utility_scripts/process_vep_tsv.py", line 82, in validate_output_cla
    raise NotADirectoryError('Output file has to be placed in an directory that already '
NotADirectoryError: Output file has to be placed in an directory that already exists!

If using ./train_input_test.tsv.gz as output argument, this error does not occur.

Expected behavior:

Giving a filename simply results in output file being created in current directory.