Having a more standardised and popular input parameter format would make it easier for other programs to create and/or read such an input parameter file without having to create a new parser for your custom format.
This would also reduce the code required in the FileHandler.py file for handling this input file format, possibly reducing bugs by using a well tested library.
JSON and XML are built into python, so those might also be nice. These are less human-readable though, so the decision is ultimately up to you depending on your concerns.
Having a more standardised and popular input parameter format would make it easier for other programs to create and/or read such an input parameter file without having to create a new parser for your custom format.
This would also reduce the code required in the FileHandler.py file for handling this input file format, possibly reducing bugs by using a well tested library.
JSON and XML are built into python, so those might also be nice. These are less human-readable though, so the decision is ultimately up to you depending on your concerns.
More info on TOML vs YAML: https://stackoverflow.com/questions/65283208/toml-vs-yaml-vs-strictyaml
For YAML PyYAML is popular. For TOML, tomllib is standardized: PEP 680 – tomllib: Support for Parsing TOML in the Standard Library