kenjfischer / expression-evaluator

A simple Python class that takes in a mathematical expression as a string, evaluates it, and returns the result.

Expression Evaluator

A simple Python class that takes in a mathematical expression as a string, evaluates it, and returns the result. Designed to be simple to use; just feed it a string, and if anything is wrong with your input it will tell you what the problem is.

Usage:

calc = Calculator.Calculator()
expr = "(17.32 * 4.3301 + (4 ^ 3)) * -(11 / (24 - -19))(3.14)"
print(calc.evaluate(expr))

Info

Recognizes the following operators: +, -, *, /, %, ^
You can enter any expression composed of these operators, digits, and parentheses. Additionally, this class can simplify any number of sequential negative signs, so it can handle statements such as "2 -- -2". Implicit multiplication by parentheses is also understood (e.g. "2(3)" would be parsed as "2*3").

Performs validation of the input. Checks for:

• Balanced parentheses
• Balanced operators
• Valid decimal points (e.g. "3.14.159" is not valid)
• No invalid characters (i.e. no characters that are not digits, decimal points, operators, or parentheses).

This was my first dive into Python, so there may be some oddities in the code.