I need to read the comparison operators from the keyboard. But I can't figure out how to take an operator from the list and compare something. Tell me please.

l =[] while True: s = str(input('Введите(>,<,==,>=,<=): ')) if not s: break l.append(s)

    2 answers 2

    You can use the operator module to find the corresponding function by the sign of the operator:

     import operator op2f = { '<': operator.lt, '<=': operator.le, '==': operator.eq, '!=': operator.ne, '>=': operator.ge, '>': operator.gt }

    To compare a, b numbers using the operators entered:

     a, b = 1, 2 L = [op2f[op](a, b) for op in iter(lambda: input('Введите(>,<,==,>=,<=): '), '')]

      It is possible through eval

       a, b = 1, 2 while True: s = str(input('Введите(>,<,==,>=,<=): ')) expr = str(a) + s + str(b) print(expr, eval(expr))

      Run:

       Введите(>,<,==,>=,<=): > 1>2 False Введите(>,<,==,>=,<=): < 1<2 True Введите(>,<,==,>=,<=): == 1==2 False Введите(>,<,==,>=,<=): >= 1>=2 False Введите(>,<,==,>=,<=): <= 1<=2 True

      But the @jfs way is safer. In the case of eval any command can be passed to you, and it will be executed. Use at your own risk.

      • You can check add set(s) <= set('!<=>') <=> set(s) <= set('!<=>') - insolor