curriculum/challenges/english/blocks/learn-special-methods-by-building-a-vector-space/65f876d17832001e8e1abb05.md
Declare a variable arg_list. Give it the value of a list comprehension that iterates over key and val for each key-value pair in vars(self).items() and computes the f-string f'{key}={val}' at each iteration.
You should declare a variable arg_list.
({ test: () => assert(runPython(`_Node(_code).find_class("R2Vector").find_function("__repr__").has_variable("arg_list")`)) })
You should assign a list comprehension that iterates over vars(self).items() to arg_list.
({ test: () => runPython(`
import ast
var = _Node(_code).find_class("R2Vector").find_function("__repr__").find_variable("arg_list")
assert isinstance(var.tree.value, ast.ListComp), "Expected arg_list to be a list comprehension"
assert (actual := var.find_comp_iters()[0].is_equivalent("vars(self).items()")), f"Expected vars(self).items(), got {actual}"
`) })
The list comprehension assigned to arg_list should use key and val to iterate over vars(self).items().
({ test: () => assert(runPython(`
_Node(_code).find_class("R2Vector").find_function("__repr__").find_variable("arg_list").find_comp_targets()[0].is_equivalent("key, val")
`)) })
The list comprehension assigned to arg_list should compute the string f'{key}={val}' for each key-value pair in vars(self).items().
({ test: () => assert(runPython(`_Node(_code).find_class("R2Vector").find_function("__repr__").find_variable("arg_list").find_comp_expr().is_equivalent("f'{key}={val}'")`)) })
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)))
--fcc-editable-region--
def __repr__(self):
pass
--fcc-editable-region--
class R3Vector(R2Vector):
def __init__(self, *, x, y, z):
super().__init__(x=x, y=y)
self.z = z
v1 = R2Vector(x=2, y=3)
v2 = R3Vector(x=2, y=2, z=3)
print(f'v1 = {v1}')
print(f'v2 = {v2}')