Equation parsing in Python

Python's own internal compiler can parse this, if you use Python notation.

If your change the notation slightly, you'll be happier.

import compilereq= "sin(x)*x**2"ast= compiler.parse( eq )

You get an abstract syntax tree that you can work with.

python parsing equation

You can use Python parser:

import parserfrom math import sinformula = "sin(x)*x**2"code = parser.expr(formula).compile()x = 10print(eval(code))

It performs better than pure eval and, of course, avoids code injection!

python parsing equation

 f = parser.parse('sin(x)*x^2').to_pyfunc()

Where parser could be defined using PLY, pyparsing, builtin tokenizer, parser, ast.

Don't use eval on user input.

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