add calc.py from ply examples
autopep8
add bool operations
remove base class
add parse method
pass test_Condition
add item support
add dict_path support
WIP comparison
WIP
Comparison, COndition, dict_path OK
add float
WIP membership
add in container
container OK
add syntax error
better syntax error
error checking
refactor condexp tests
rename conditional_parser to condexp_parser