Math Engine, eval()-free expression interpreter for Python (opens in new tab)

A safe evaluation engine for mathematical expressions, built from scratch: tokenizer, recursive-descent parser, AST, linear equation solver and a type-safe output system, entirely without Python's eval(). Live on PyPI, 399 tests, 90% coverage, green across five Python versions. The challenge The obvious way to evaluate an expression like 3 + 4 * 2 in Python is a single line: eval("3 + 4 * 2"). That very line is the problem. eval() executes arbitrary Python code, a string disguised as numeric ...