curriculum/challenges/english/blocks/learn-interfaces-by-building-an-equation-solver/663b7fefd437bd984e091cbf.md
Next, create a new class named QuadraticEquation and make it inherit from Equation. You'll use this new class to represent quadratic equations, which are second-degree equations having the form $ax^2 + bx + c = 0$.
Inside your new class, define a degree class attribute with the value 2, which is the degree of a quadratic equation. Also, define the solve and analyze methods. You will take care of the implementation in the following steps.
You should create a new class named QuadraticEquation and make it inherit from the Equation class.
({ test: () => assert(runPython(`_Node(_code).find_class("QuadraticEquation").inherits_from("Equation")`)) })
You should define a solve method within the QuadraticEquation class.
({ test: () => assert(runPython(`_Node(_code).find_class("QuadraticEquation").has_function("solve")`)) })
Your solve method should take a single parameter, self.
({ test: () => assert(runPython(`_Node(_code).find_class("QuadraticEquation").find_function("solve").has_args("self")`)) })
You should define an analyze method within the QuadraticEquation class.
({ test: () => assert(runPython(`_Node(_code).find_class("QuadraticEquation").has_function("analyze")`)) })
Your analyze method should take a single parameter, self.
({ test: () => assert(runPython(`_Node(_code).find_class("QuadraticEquation").find_function("analyze").has_args("self")`)) })
You should define a degree class attribute within the QuadraticEquation class and assign it the value 2.
({ test: () => assert(runPython(`_Node(_code).find_class("QuadraticEquation").find_variable("degree").is_equivalent("degree = 2")`)) })
from abc import ABC, abstractmethod
class Equation(ABC):
degree: int
def __init__(self, *args):
if (self.degree + 1) != len(args):
raise TypeError(
f"'Equation' object takes {self.degree + 1} positional arguments but {len(args)} were given"
)
if any(not isinstance(arg, (int, float)) for arg in args):
raise TypeError("Coefficients must be of type 'int' or 'float'")
if args[0] == 0:
raise ValueError("Highest degree coefficient must be different from zero")
self.coefficients = {(len(args) - n - 1): arg for n, arg in enumerate(args)}
def __init_subclass__(cls):
if not hasattr(cls, "degree"):
raise AttributeError(
f"Cannot create '{cls.__name__}' class: missing required attribute 'degree'"
)
def __str__(self):
terms = []
for n, coefficient in self.coefficients.items():
if not coefficient:
continue
if n == 0:
terms.append(f'{coefficient:+}')
elif n == 1:
terms.append(f'{coefficient:+}x')
equation_string = ' '.join(terms) + ' = 0'
return equation_string.strip('+')
@abstractmethod
def solve(self):
pass
@abstractmethod
def analyze(self):
pass
class LinearEquation(Equation):
degree = 1
def solve(self):
a, b = self.coefficients.values()
x = -b / a
return x
def analyze(self):
slope, intercept = self.coefficients.values()
return {'slope': slope, 'intercept': intercept}
--fcc-editable-region--
--fcc-editable-region--
lin_eq = LinearEquation(2, 3)
print(lin_eq)