I'm a super beginner to python and know nothing about it and currently for my class we are tasked to find a closest point to a list of other points:

def find_closest(start_point, remaining_points) :
    for element in list(remaining_points) :
        result = distance(start_point, element)
        print(result)

(I defined a distance function that calculates the direct distance between two points)

I then input the following code:

find_closest((1,2),[(3,4),(5,6),(7,8)])

And this gives me answers for the list such like:

2.8284271247461903
5.656854249492381
8.48528137423857

My question is, how do I code into the find_closest function a way to find the minimum value from the result and then print that element's point, i.e: in the answer of simply:

(3,4)

Sorry if this seems too simple, I've tried searching many sources and couldn't find a simple answer as we cant use advanced python and are restricted to if loops and elif etc... Thanks guys!

CodePudding user response：

Solution

You can use the min function of python with the key argument like this:

def find_closest(start_point, remaining_points):
    return min(remaining_points, key=lambda a: distance(start_point, a))

Links for more information

• min function: https://www.programiz.com/python-programming/methods/built-in/min
• lambda function: https://www.w3schools.com/python/python_lambda.asp

CodePudding user response：

A quick and straightforward solution would be to create a list of results and then corroborate the index with your list of remaining points (because they are inherently lined up). Below is a step-by-step process to achieving this, and at the very bottom is a cleaned-up version of the code.

def find_closest(start_point, remaining_points):
    results = []  # list of results for later use
    for element in list(remaining_points):
        result = distance(start_point, element)
        results.append(result)  # append the result to the list

    # After iteration is finished, find the lowest result
    lowest_result = min(results)
    # Find the index of the lowest result
    lowest_result_index = results.index(lowest_result)
    # Corroborate this with the inputs
    closest_point = remaining_points[lowest_result_index]
    # Return the closest point
    return closest_point

Or to simplify the code:

def find_closest(start_point, remaining_points):
    results = []
    for element in remaining_points:
        results.append(distance(start_point, element))
    
    return remaining_points[results.index(min(results))]