Function not defined after declaration in python3

Question

Using python 3: I have three functions: montePi, isInCircle and main. I need to have the isInCircle called by montePi. The function will work, it just says that isInCircle is not defined. How can I define it?

import random
import math

def montePi(numDarts):

    inCircle = 0

    def isInCircle(x, y, r):
        r = 1
        d = math.sqrt(x**2 + y**2)
        if d <= r:
            return True
        else:
            return False

    for i in range(numDarts):
        x = random.random()
        y = random.random()
        d = math.sqrt(x**2 + y**2)
        if d <= 1:
            inCircle = inCircle +1
        pi = inCircle / numDarts * 4
    return pi

def main():
    print(montePi(100))
    print(montePi(1000))
    print(montePi(10000))
    print(montePi(100000))
main()

Why not just define `isInCircle` outside of `montePi` and then call it? — Christian Dean, Jan 30 '18 at 21:22
I guess I'm having trouble where to define it outside of montePi and how to call it. I think I'm confused on how to connect the two — Emma Steele, Jan 30 '18 at 21:30
For a hard-coded radius of 1, the call to `math.sqrt` is unnecessary. — chepner, Jan 30 '18 at 21:34
@EmmaSteele There's no difference in how you connect them. `if isInCircle(x, y, 1):` — Barmar, Jan 30 '18 at 21:36
`pi = inCircle / numDarts * 4` doesn't need to be in the loop. — Barmar, Jan 30 '18 at 21:37

Carol Chen · Answer 1 · 2018-01-30T21:38:31.123

Because function isInCircle is defined in montePi, it can be called within montePi but not other functions as it is local. If you define isInCircle outside of montePi then you'll be able to call it from main.

Not sure what you're trying to program here, but there seems to be a chance that this question, regarding functions within functions can help you decide what you want here. Here is a question that covers how scopes work.

Should you need to call isInCircle from main or outside main, then this is how it should be formatted;

import random
import math

def isInCircle(x, y, r):
    r = 1
    d = math.sqrt(x**2 + y**2)
    if d <= r:
        return True
    else:
        return False

def montePi(numDarts):

    inCircle = 0

    for i in range(numDarts):
        x = random.random()
        y = random.random()
        d = math.sqrt(x**2 + y**2)
        if d <= 1:
            inCircle = inCircle +1
        pi = inCircle / numDarts * 4
    return pi

def main():
    print(montePi(100))
    print(montePi(1000))
    print(montePi(10000))
    print(montePi(100000))
main()

Function not defined after declaration in python3

1 Answers1