Таблица значений функций

from math import sqrt

class SqrtFun:
  def call(self, x):
    return sqrt(x)

class Const:
  def __init__(self, value):
    self.value = value

    def call(self, x):
      return self.value

class Identity:
  def call(self, x):
    return x

class Expression:
  def __init__(self, f1, op, f2):
    self.f1 = f1
    self.op = op
    self.f2 = f2

  def call(self, x):
    a = self.f1.call(x)
    b = self.f2.call(x)
    if self.op == '+':
      return a + b
    elif self.op == '-':
      return a - b
    elif self.op == '*':
      return a * b
    elif self.op  == '/':
      return a / b

def main():
  functions = {'x': Identity(), 'sqrt_fun': SqrtFun()}
  n = int(input())
  for _ in range(n):
    command, *args = input().split()
    if command == 'define':
      name, f1, op, f2 = args
      if f1.isdigit() or (f1[0] == '-' and f1[1:].isdigit()):
        f1 = Const(int(f1))
      else:
        f1 = functions[f1]
      if f2.isdigit() or (f2[0] == '-' and f2[1:].isdigit()):
        f2 = Const(int(f2))
      else:
        f2 = functions[f2]
      functions[name] = Expression(f1, op, f2)
    elif command == 'calculate':
      name, *x_values = args
      print(' '.join(str(functions[name].call(int(x))) for x in x_values))

if __name__ == '__main__':
  main()