curriculum/challenges/english/blocks/learn-special-methods-by-building-a-vector-space/65fc8fa7e7860407ab479bf0.md
It's time to test the multiplication. Declare a new variable v5 and assign it the scalar multiplication v1 * 3.
Then, call the print function and pass it the following f-string: f'v1 * 3 = {v5}'.
You should declare a new variable v5 and assign it the scalar multiplication v1 * 3.
({ test: () => assert(runPython(`_Node(_code).find_variable("v5").is_equivalent("v5 = v1 * 3")`)) })
You should print the f-string f'v1 * 3 = {v5}'.
({ test: () => assert(runPython(`_Node(_code).has_call("print(f'v1 * 3 = {v5}')")`)) })
class R2Vector:
def __init__(self, *, x, y):
self.x = x
self.y = y
def norm(self):
return sum(val**2 for val in vars(self).values())**0.5
def __str__(self):
return str(tuple(getattr(self, i) for i in vars(self)))
def __repr__(self):
arg_list = [f'{key}={val}' for key, val in vars(self).items()]
args = ', '.join(arg_list)
return f'{self.__class__.__name__}({args})'
def __add__(self, other):
if type(self) != type(other):
return NotImplemented
kwargs = {i: getattr(self, i) + getattr(other, i) for i in vars(self)}
return self.__class__(**kwargs)
def __sub__(self, other):
if type(self) != type(other):
return NotImplemented
kwargs = {i: getattr(self, i) - getattr(other, i) for i in vars(self)}
return self.__class__(**kwargs)
def __mul__(self, other):
if type(other) in (int, float):
kwargs = {i: getattr(self, i) * other for i in vars(self)}
return self.__class__(**kwargs)
elif type(self) == type(other):
args = [getattr(self, i) * getattr(other, i) for i in vars(self)]
return sum(args)
return NotImplemented
class R3Vector(R2Vector):
def __init__(self, *, x, y, z):
super().__init__(x=x, y=y)
self.z = z
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v1 = R2Vector(x=2, y=3)
v2 = R2Vector(x=0.5, y=1.25)
print(f'v1 = {v1}')
print(f'v2 = {v2}')
v3 = v1 + v2
print(f'v1 + v2 = {v3}')
v4 = v1 - v2
print(f'v1 - v2 = {v4}')
--fcc-editable-region--