I experienced a strange behavior of bash shell tab completion while trying to run a python code.When I use more than one character followed by - prefixed argument, I am able to select the a file using tab completion, but with just one character it completely fails. Here are some examples: #failed python prepare_yaml_files.py -i in<tab><tab>#succeed: though `-in` is not valid python prepare_yaml_files.py -in in<tab><tab>#succeed: valid argument python prepare_yaml_files.py --in in<tab><tab>I wonder why this happens. Do I need to set some preference in .bashrc to address this. 
File listing on tab completion
bash;python;autocomplete