calcit.py

#!/usr/bin/python3

import sys
from math import *
# Experiment evaluating math expressions. Not unique.

try:
    # Put quotes around your expression on the command line
    inputs = (sys.argv)
    # Remove the executing script name from the input dict (array)
    expression = inputs[1:]
    # Convert the input dict to a string
    expression = " ".join(str(x) for x in expression)

    if not isinstance(expression, str):
        raise TypeError('The expression must be a string.')
    if not expression:
        raise ValueError('The expression cannot be empty.')
    # return eval(expression, namespace)
    # Print that to the terminal without a newline char
    print(f"{expression} =", end=" ", file=sys.stdout, flush=True)
except Exception as err:
    raise RuntimeError("Evaluating expression '%s' failed: %s"
            % (expression, err))

try:
    # this dict started with a honeybot plugin by Abdur-Rahmaan Janhangeer
    # https://github.com/pyhoneybot/honeybot/blob/master/src/honeybot/plugins/downloaded/calc/main.py
    # I added a few more functions from: https://www.w3schools.com/python/module_math.asp
    safe_dict = {
        "acos": acos,
        "asin": asin,
        "atan": atan,
        "atan2": atan2,
        "ceil": ceil,
        "cos": cos,
        "cosh": cosh,
        "degrees": degrees,
        "e": e,
        "exp": exp,
        "fabs": fabs,
        "factorial": factorial,
        "floor": floor,
        "fmod": fmod,
        "frexp": frexp,
        "gcd": gcd,
        "hypot": hypot,
        "isqrt": isqrt,
        "ldexp": ldexp,
        "log": log,
        "log2": log2,
        "log10": log10,
        "modf": modf,
        "pi": pi,
        "pow": pow,
        "prod": prod,
        "radians": radians,
        "remainder": remainder,
        "sin": sin,
        "sinh": sinh,
        "sqrt": sqrt,
        "tan": tan,
        "tanh": tanh,
        "trunc": trunc
    }
    # Thie approach immediately below is unsafe in an uncontrolled environment
    #     print("{}".format(eval(expression)))
    # The approach below is safer - with sanity-checking/constraining of inputs
    print("{}".format(eval(expression, {"__builtins__": None}, safe_dict)))
except Exception as ex:
    print(f"error: {__file__}: {ex}")