function handling

[JohnCrichton]

Hi All!
I'm pretty new to Python coding and I'm doing some stuff while I learn the language, I have some experience with Matlab especially for mathematical computation so I'm not totally new to coding.

But here is my problem:

I have made a function that solves f(x) = 0 and returns x. It is a standard bysection method and it works well.

What I have done so far was to define a function that I then fed to the bysection:

def my_fun(x):
y = x*2 + 4
return y

def main()
x = bysection(my_fun)
print(x)
return

This configuration WORKS, it gives me back the correct x and produces no errors.

The problem is when I want to have my_fun function of a parameter as well.

def my_fun(x, b):
y = x*2 + b
return y

The bisection function solves only f(x) = 0 and not f(x,b) = 0. What I want to do is to pass to the bysection my_fun where x is free and b is assigned:

def main()
b = 4
x = bysection(my_fun(x, b))
print(x)
return

Of course this doesn't work, do you guys have any idea? Matlab allowed me to define the function INSIDE the main, so b was already assigned, but in Python I have to define the function and then assign only b but keeping x as the only variable.

Basically can I go from:

function(x,b) to function(x) by assigning a value for b?

Thanks in advance for your help!