在其他函数中调用函数？

Question

I'm really stuck with this, I need to call a function within another function changing the argument while inside but it keeps me saying 'float' object is not callable.

for example:

def functioncall(f,epsilon):
   guess = 1.0
   for i in range(100):
      if f(guess) - guess < epsilon:
        return guess
      else:
        guess = f(guess)

gives me

File "C:/Users/Apoo/Dropbox/6.00x/midTermQuiz1/problem8.py", line 16, in functioncall
    if f(guess) - guess < epsilon:
TypeError: 'float' object is not callable

I understood that doing so I'm calling the value of the function f, which is a float in my case, but how can I change that?

Answer 1

You are actually passing the return value of the function f instead of the function object itself.

use just : functioncall(f,0.001) when calling functioncall

if you do something like functioncall(f(<int here>),0.001) , then it sends the value returned by f(<int here>) as the first argument and calling (guess) on it raised the Error.

Answer 2

For your code as written to work, the first argument passed to functioncall must be a function or other callable object. You are passing an int or float.