Python3, best alternatives to eval()? (input as an expression)

Question

I'm using Python 3.

I suppose the best way to ask this is how can I input an expression without using eval(input("Input: ")) ?

I'm a simple user right now, so what I needed eval for was an algebra calculator.

Answer 1

If you're the only person using that app and thus don't need to be worried about security issues, just keep using eval() or exec() .

Otherwise, just use a safe library for the specific task you need. Eg numexpr I guess for a calculator.

Answer 2

根据表达式的复杂程度， ast.literal_eval可能是更安全的替代方案。

Answer 3

how can I input an expression without using eval(input("Input: "))

simply don;t use eval . In Python 3.x, input is the replacement for raw_input so, you don;t need eval. You can simply write your statement as input("Input: ")

Moreover, in Python 2.X, you should have used raw_input("Input: ") instead of eval(input("Input: "))