UnknownAMD

from math import sin, cos, tan, exp, log, sqrt, pow, pi, e

def parse_function(expr):
    def f(x):
        try:
            return eval(expr, {"x": x, "sin": sin, "cos": cos, "tan": tan,
                               "exp": exp, "log": log, "sqrt": sqrt,
                               "pow": pow, "pi": pi, "e": e, "__builtins__": None})
        except:
            return None