Error:- '_io.TextIOWrapper' object is not callable

Question

I have written a code to find the roots of an equation by bisection method.
I am trying to append my loop index and the difference between two solutions every iteration of the loop, but I am getting the error mentioned in the title of the question.

Also, I saw the answers to similar questions where people had already suggested to use the write method instead of calling it directly however, that just gives me an error saying that 'builtin_function_or_method' object has no attribute 'write'

My code:-

#Function to solve by bisection method
def bisection(f,a,b,fileName,tol = 10**-6):
    #making sure a is left of b
    if(a>b):
        temp = b
        b = a
        a = temp
    
    #Bracketing the roots
    a,b = bracketChecker(f,a,b)
    if((a,b) == False): return None

    #Checking if either of a or b is a root
    if(f(a)*f(b) == 0):
        if(f(a)==0):
            return a
        else: return b

    else:
        i = 0
        c = 0
        while(abs(a-b) > tol and i<200):
            c_old = c
            c = (a+b)/2.0
            abserr = c - c_old
            if (abs(f(c)) < tol):
                return c
            if (f(a)*f(c)<0):
                b = c
            else: a = c

            #Appending the data
            with open(fileName, 'a') as f:
                print(i,abserr, file=f)             #The error is occuring here
            i += 1
    return (a+b)/2.0

Answer 1

It works fine, the problem was only occurring because i had named the file as f, which is the same variable i used for my function. Hence, the errors... Thank you @mibu for pointing that out