AttributeError: Computing the distance between two points

user_19801291 0
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I am doing an exercise in the textbook Think Python by Allen Downey. I am sure that the code is correct but it keeps showing the same problem:

Traceback (most recent call last):
  File "C:/Users/ADMIN/PycharmProjects/ProgrammingFundamental101/EXTRA EFFORTS/Classes_and_Objects.py", line 80, in <module>
    print(distance_between_points(blank.x, blank.y))
  File "C:/Users/ADMIN/PycharmProjects/ProgrammingFundamental101/EXTRA EFFORTS/Classes_and_Objects.py", line 74, in distance_between_points
    dx = p1.x - p2.x
AttributeError: 'float' object has no attribute 'x'

The code is below:


def distance_between_points(p1, p2):
    dx = p1.x - p2.x
    dy = p1.y - p2.y
    dist = math.sqrt(dx**2 + dy**2)
    return dist

print(distance_between_points(blank.x, blank.y))

Both points blank.x and blank.y have been defined and assigned with values of 3 and 4.

What is going wrong with the arguments or the parameter?

attributeerror python
3 Answers

thanks so much for your effort and time.

After reviewing your suggestions and taking another look through the material. I figured it out.

I created two different points to be used as arguments and it worked!

b = Point()
b.x = 0
b.y = 0

g = Point()
g.x = 3
g.y = 4

print('distance', distance_between_points(b, g))

distance 5.0

Again, thanks so much for such prompt responses!

user_198012910

Obviously the code cannot be correct. Otherwise it would not throw an error. :) The error message tells you, what is wrong. In this line:

dx = p1.x - p2.x

You are accessing the x property of p1 and of p2. At least one of those two (though I am guessing both) is a float type object, which does not have an attribute named x.

Unfortunately, you did not post the context, i.e. where blank comes from. So I can only guess that it is some sort of object representing a point in 2D-space, which has an x and a y attribute representing the point's coordinates as floats. I would assume that the distance_between_points function expects the arguments to be instances of that same point class. And instead (again, I am just guessing here) you are passing the x-coordinate of a point as the first and the y-coordinate as the second argument to the function instead of two different point objects.

If you post the entire relevant context (where blank comes from), we could verify this.

user_197707950

I'm assuming that blank is a Point object.

The function is expecting p1 and p2 to be Point objects. This means that what is needed is

distance_between_points(some_point, another_point)

If python sees some_point.x it is no longer a Point object, it's the x coordinate of that some_point object.

In the code p1 is blank.x, which means when it does p1.x it is doing blank.x.x, which is why python raises that error.

user_38084300
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