python-almost_a_circle

Python - Almost a circle

This project was developed in object-oriented programming with three classes, a base and two other subclasses to represent rectangles and squares. Tests were also created for all classes using the unittest module.

This project contains these topics:

• Imports
• Exceptions
• Private attributes
• Getter/setter
• Class/static methods
• Inheritance
• File I/O
• *args and **kwargs
• JSON serialization/deserialization
• Unittesting

main_files/ - Main functions provided by Holberton School to test the files.

Tests

• tests/test_models/: Test files using unittest:
  • test_base.py
  • test_rectangle.py
  • test_square.py

Classes

Base

base.py - Represents the "base" class for all other classes in the project. Includes:

• Private class attribute __nb_objects = 0.
• Public instance attribute id.
• Class constructor def __init__(self, id=None).
  • If id is None, increments __nb_objects and assigns its value to the public instance attribute id.
  • Otherwise, sets the public instance attribute id to the provided id.
• Static method def to_json_string(list_dictionaries) that returns the JSON string representation of list_dictionaries.
  • If list_dictionaries is None or empty, returns the string "[]".
• Class method def save_to_file(cls, list_objs) that writes the JSON string representation of list_objs to a file.
  • The parameter list_objs is a list of instances who inherits of Base.
  • If list_objs is None, saves an empty list.
  • The file is saved with the name <classname>.json.
  • Overwrites the file if it already exists.
• Static method def from_json_string(json_string) that returns the list of the JSON string representation json_string.
  • The parameter json_string is a string representing a list of dictionaries.
  • If json_string is None or empty, the function returns an empty list.
• Class method def create(cls, **dictionary) that returns an instance with all attributes already set.
  • Instantiates an object with the attributes given in **dictionary.
• Class method def load_from_file(cls) that returns a list of instances.
  • Reads from the JSON file <classname>.json.
  • If the file doesn't exist, the function returns an empty list.

Rectangle

rectangle.py - Represents a rectangle. Inherits from Base with:

• Private instance attributes __width, __height, __x, and __y.
  • Each private instance attribute features its own getter/setter.
• Class constructor def __init__(self, width, height, x=0, y=0, id=None).
  • If either of width, height, x, or y is not an integer, raises a TypeError exception with the message <attribute> must be an integer.
  • If either of width or height is <= 0, raises a ValueError exception with the message <attribute> must be > 0.
  • If either of x or y is less than 0, raises a ValueError exception with the message <attribute> must be >= 0.
• Public method def area(self) that returns the area of the Rectangle instance.
• Public method def display(self) that prints the Rectangle instance to stdout using the character #.
  • Prints new lines for the y coordinate and spaces for the x coordinate.
• Overwrite the __str__ method to returns a Rectangle instance in the format [Rectangle] (<id>) <x>/<y> - <width>/<height>.
• Public method def update(self, *args, **kwargs) that updates an instance of a Rectangle with the given attributes.
  • *args is supplied in the following order:
    • 1st: id.
    • 2nd: width.
    • 3rd: height.
    • 4th: x.
    • 5th: y.
  • **kwargs is a dictionary of new key/value attributes to update the Rectangle instance.
  • **kwargs is skipped if *args exists.
• Public method def to_dictionary(self) that returns the dictionary representation of a Rectangle instance.

Square

square.py - Represents a square. Inherits from Rectangle with:

• Class constructor def __init__(self, size, x=0, y=0, id=None).
  • The width and height of the Rectangle superclass are assigned using the value of size.
• Overwrite the __str__ method to print a Square instance in the format [Square] (<id>) <x>/<y> - <size>.
• Public method def update(self, *args, **kwargs) that updates an instance of a Square with the given attributes.
  • *args must be supplied in the following order:
    • 1st: id.
    • 2nd: size.
    • 3rd: x.
    • 4th: y.
  • **kwargs is a dictoinary of new key/value attributes to update the Square instance.
  • **kwargs is skipped if *args exists.
• Public method def to_dictionary(self) that returns the dictionary representation of a Square instance.

Author

• Felipe Villamizar - GitHub