Returning a Value vs Mutating the Object: Writing to_origin

Why does `distance` hand back a number while `to_origin` returns nothing at all — and what does each one do to `self`?

Finger exercises

Short drills on what this video just taught. Write the code, run the checks, and reveal the answer only if you are stuck.

0 / 5 passed

The Point class below already has __init__ and distance. Add a method named to_origin that takes only self and always leaves the point sitting at (0, 0), wherever it happened to be before. It hands nothing back — its whole job is to overwrite the object's own data.

Then call it on point, which starts at (3, 4), and assign to after the tuple (point.x, point.y).
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class Point(object): """ A point made up of an x and y numerical value """ def __init__(self, xval, yval): """ Sets the x and y values """ self.x = xval self.y = yval def distance(self, other): """ Returns the euclidean distance between two Point objects """ x_diff_sq = (self.x - other.x) ** 2 y_diff_sq = (self.y - other.y) ** 2 return (x_diff_sq + y_diff_sq) ** 0.5 # your code here: add the to_origin method point = Point(3, 4) # Run your new method on point, then record where point ends up. after = ... # your code here
class Point(object): """ A point made up of an x and y numerical value """ def __init__(self, xval, yval): """ Sets the x and y values """ self.x = xval self.y = yval def distance(self, other): """ Returns the euclidean distance between two Point objects """ x_diff_sq = (self.x - other.x) ** 2 y_diff_sq = (self.y - other.y) ** 2 return (x_diff_sq + y_diff_sq) ** 0.5 # your code here: add the to_origin method point = Point(3, 4) # Run your new method on point, then record where point ends up. after = ... # your code here
Python runs in your browser
⌘/Ctrl + Enter runs
`Point` has a method named `to_origin`
`to_origin` hands nothing back
moves any point to (0, 0)
`after` records where `point` ended up

←Previous Data Attributes vs Parameter Names: What self Guarantees Next Composition and ValueError: A Circle Made of Coordinate Objects →

Returning a Value vs Mutating the Object: Writing to_origin

Why does `distance` hand back a number while `to_origin` returns nothing at all — and what does each one do to `self`?

Finger exercises

Short drills on what this video just taught. Write the code, run the checks, and reveal the answer only if you are stuck.

0 / 5 passed

The Point class below already has __init__ and distance. Add a method named to_origin that takes only self and always leaves the point sitting at (0, 0), wherever it happened to be before. It hands nothing back — its whole job is to overwrite the object's own data.

Then call it on point, which starts at (3, 4), and assign to after the tuple (point.x, point.y).
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class Point(object): """ A point made up of an x and y numerical value """ def __init__(self, xval, yval): """ Sets the x and y values """ self.x = xval self.y = yval def distance(self, other): """ Returns the euclidean distance between two Point objects """ x_diff_sq = (self.x - other.x) ** 2 y_diff_sq = (self.y - other.y) ** 2 return (x_diff_sq + y_diff_sq) ** 0.5 # your code here: add the to_origin method point = Point(3, 4) # Run your new method on point, then record where point ends up. after = ... # your code here
class Point(object): """ A point made up of an x and y numerical value """ def __init__(self, xval, yval): """ Sets the x and y values """ self.x = xval self.y = yval def distance(self, other): """ Returns the euclidean distance between two Point objects """ x_diff_sq = (self.x - other.x) ** 2 y_diff_sq = (self.y - other.y) ** 2 return (x_diff_sq + y_diff_sq) ** 0.5 # your code here: add the to_origin method point = Point(3, 4) # Run your new method on point, then record where point ends up. after = ... # your code here
Python runs in your browser
⌘/Ctrl + Enter runs
`Point` has a method named `to_origin`
`to_origin` hands nothing back
moves any point to (0, 0)
`after` records where `point` ended up

←Previous Data Attributes vs Parameter Names: What self Guarantees Next Composition and ValueError: A Circle Made of Coordinate Objects →