This is a toy one-file application to manage persistent key-value string data.
The file is *both* the application and its data. When you run any of the commands described in `escher.py --help`, the file will be executed and, after data change, it will rewrite itself with updated data.
You can copy the file with whatever name to create multiple datasets. Remember that the data will be copied with the file. Each file must be readable, writable, and executable.