pyxp

Python library for construct arithmetic expression (including function calls), which can be serialized to/deserialized from json.

Cases

• Console game DUST 514 by CCP, on PlayStation, used for formula updating.

Installation

easy_install pyxp

or

pip install pyxp

Example

Construct Expression, Serialization/Deserialization.

from pyxp import val, from_json, context

# Expression variables could be assign to python variables to use later,
# or use them inline, see 'val.my_sum'.
double = val.double
add = val.add
a = val.a
b = val.b

exp = double(a + b) + add(a, b) - (val.my_sum(a, b) << 1)

# Serialize to string, so you could send it over network. 
json_str = exp.to_json()

# Deserialization
exp_deserialized = from_json(json_str)

Calculation

# Functions and variables sharing the same namespace.
context_ = context(
    a=10,
    b=2,
    double=lambda x: x * 2,
    add=lambda x, y: x + y,
    my_sum=lambda *args: sum(args),
)

actual = exp.calc(context_)
assert actual == 12

More examples Test Cases