Can you explain the working principle and main ideas of the Builder pattern?

The Builder pattern is used for step-by-step creation of complex objects, separating the construction process from the presentation. It is convenient when an object has many parameters, some of which are optional.

Main ideas:

• A separate Builder class is created, which contains methods for setting parameters.
• Builder methods return the Builder itself, allowing for method chaining (fluent interface).
• At the end, the build() method is called, which returns the finished object.

Example in Python:

class Car:
    def __init__(self, color=None, engine=None, seats=None):
        self.color = color
        self.engine = engine
        self.seats = seats

class CarBuilder:
    def __init__(self):
        self.color = None
        self.engine = None
        self.seats = None

    def set_color(self, color):
        self.color = color
        return self

    def set_engine(self, engine):
        self.engine = engine
        return self

    def set_seats(self, seats):
        self.seats = seats
        return self

    def build(self):
        return Car(self.color, self.engine, self.seats)

Usage: builder = CarBuilder() car = builder.set_color('red').set_engine('V8').set_seats(4).build()

This approach improves code readability and simplifies the creation of objects with many parameters.