pyisheval

pyisheval is a Rust library that allows you to evaluate Python-like expressions.
It's not a full Python interpreter, but it supports a subset of Python-like syntax:

• Arithmetic operations: +, -, *, /, //, %, **, >, <, >=, <=, ==, !=
• Variables and assignments
• Lambda expressions (lambda x: x + 1)
• Built-in functions: abs, max, min, int, float, len
• List and dictionary literals
• List comprehensions: [y * 2 for y in x]

No classes, functions (def), or control structures are supported.

Installation

cargo add pyisheval

Example

use pyisheval::Interpreter;

fn main() {
    let mut interp = Interpreter::new();

    // Assign variables
    interp.eval("x = 10").unwrap();
    interp.eval("y = 20").unwrap();

    // Arithmetic
    let val = interp.eval("x + y * 2").unwrap();
    println!("{}", val); // 50

    // Lambda
    interp.eval("inc = lambda a: a + 1").unwrap();
    let val = interp.eval("inc(x)").unwrap();
    println!("{}", val); // 11
}

Why

This library aims to provide a lightweight and embedded Python-like expression evaluator for scenarios where you want to let users provide arithmetic expressions or simple lambdas without embedding a full Python interpreter.