This is the AirBnB-Clone project, which is a great introduction to OOP+Web interactions, You can find below a description of the project itself plus the python concepts used in coding it.
This also is a guide to various aspects of Python development, covering topics such as creating Python packages, building a command interpreter, implementing unit testing, serializing and deserializing classes, working with JSON files, managing datetime, understanding UUIDs, utilizing *args and **kwargs, and handling named arguments in functions.
- Description
- Files and Dirs
- Usage
- Creating a Python Package
- Creating a Command Interpreter in Python
- Unit Testing in Python
- Serialization and Deserialization of Classes
- Reading and Writing JSON Files
- Managing Datetime in Python
- Understanding UUIDs
- Using *args in Python
- Using **kwargs in Python
- Handling Named Arguments in Functions
The goal of the project is to deploy on a server a simple self-made copy of the AirBnB website logic.
-
I won’t implement all the features, only some of them to cover all fundamental concepts of the higher level programming track (i,e:TOC).
-
In this repo we are only interested in generating the following parts of the larger project mentioned above:
- Creating the Data model of the project.
- Managing objects via a Console.
- Store and persist objects in a 'JSON' file.
The aim is to manipulate a powerful storage system. This storage engine will give us an abstraction between “an object” and “How they are stored and persisted”. This means: from the$ console
code (the command interpreter itself) and from the front-end and RestAPI we will build later, we won’t have to pay attention (take care) of how objects are stored.
-
This abstraction will also allow us to change the type of storage easily without updating all of the codebase.
-
The
$ console
will be a tool to validate this storage engine.
models
directory will contain all classes used for the entire project. A class, called “model” in a OOP project is the representation of an object/instance.tests
directory will contain all unit tests.console.py
file is the entry point of our command interpreter.models/base_model.py
file is the base class of all our models. It contains common elements:- attributes:
id
,created_at
andupdated_at
- methods:
save()
andto_json()
- attributes:
models/*.py
other classes module.:models/engine
directory will contain all storage classes (using the same prototype). For the moment will have only one:file_storage.py
.
Try it yourself!
1- git clone https://github.com/LWSSIM/AirBnB_clone/
2- cd AirBnB_clone
3- ./console
$
Welcome to the AirBnB CLI tool.
---Type help or ? to list commands.
(hbnb)
- The CLI supports many commands to manipulate objects plus allow for easy interaction with the storage engine (a .json file);
Discover all the available commands and their usage with help
or ?
:
(hbnb) help
Documented commands (type help <topic>):
****************************************
EOF all clear count create destroy help quit show update
Miscellaneous help topics:
**************************
precmd
(hbnb) ? all
[Usage]: all [<className>]
Prints all instances string representations
Ex: $ all BaseModel or $ all
Sformat:
<ClassName>.all()
(hbnb)
To create a Python package, follow these steps:
-
Project Structure: Organize your project with a specific directory structure. A typical structure might include a
src
directory for source code and atests
directory for tests. -
Create
setup.py
: Define the package details, dependencies, and other metadata in asetup.py
file. -
Write Code: Develop your Python code and organize it into modules within the package.
-
Init File: In each directory that should be treated as a package, create an
__init__.py
file (can be empty). -
Install and Test Locally: Install your package locally using
pip install .
and test it. -
Distribution: To distribute your package, you can use tools like
setuptools
and upload it to the Python Package Index (PyPI).
For more details, refer to the official Python Packaging User Guide.
To create a command interpreter in Python using the cmd
module:
-
Import the Module: Import the
cmd
module, which provides theCmd
class for building command interpreters. -
Create a Subclass: Subclass the
Cmd
class and override its methods such asdo_command
for handling commands. -
Define Commands: Implement methods named
do_<command>
to define the behavior for each command. -
Run the Interpreter: Instantiate your class and call its
cmdloop()
method to start the command interpreter loop.
Example:
import cmd
class MyCmdInterpreter(cmd.Cmd):
def do_hello(self, arg):
print("Hello, " + arg)
if __name__ == "__main__":
interpreter = MyCmdInterpreter()
interpreter.cmdloop()
Unit testing is a software testing method where individual units or components of a program are tested in isolation to ensure they function as intended. In Python, the unittest
module provides a framework for writing and running tests.
-
Organize Test Files: Create a separate
tests
directory in your project and organize test files corresponding to the modules or packages being tested. -
Use Test Classes: Create test classes using the
unittest.TestCase
class. Define test methods within these classes. -
Assertions: Use assertions such as
assertEqual
,assertTrue
, etc., to verify that the code behaves as expected. -
Test Discovery: Run tests using the
unittest
module's test discovery mechanism, e.g.,python -m unittest discover tests
. -
Test Coverage: Monitor test coverage with tools like
coverage.py
to ensure a comprehensive set of tests.
For more information, refer to the unittest documentation.
1- Generate a dictionary representation of an instance
2- Re-create an instance from another one by using a dictionary representation
<class 'BaseModel'> -> to_dict() -> <class 'dict'> -> <class 'BaseModel'>
3-We can then convert a self.dict dictionary to a string and store
it in JSON an then load
it after:
<class 'BaseModel'> -> to_dict() -> <class 'dict'> -> JSON dump -> <class 'str'> -> FILE -> <class 'str'> -> JSON load -> <class 'dict'> -> <class 'BaseModel'>
FILE
can become a DataBase
with a future storage engine update.
To read and write JSON files in Python:
import json
# Writing to a JSON file
data = {"key": "value"}
with open('data.json', 'w') as json_file:
json.dump(data, json_file)
# Reading from a JSON file
with open('data.json', 'r') as json_file:
loaded_data = json.load(json_file)
print(loaded_data)
Ensure that the data being written to JSON is serializable, and handle exceptions.
To manage datetime in Python, use the datetime
module:
from datetime import datetime, timedelta
# Current date and time
now = datetime.now()
print("Current date and time:", now)
# Formatting
formatted_date = now.strftime("%Y-%m-%d %H:%M:%S")
print("Formatted date:", formatted_date)
# Adding time delta
new_date = now + timedelta(days=7)
print("Date after 7 days:", new_date)
Explore the datetime
module for various functionalities like parsing, comparisons, and arithmetic operations.
UUID (Universally Unique Identifier) is a 128-bit identifier that is guaranteed to be unique across both space and time. In Python, you can generate UUIDs using the uuid
module:
import uuid
# Generate a UUID
new_uuid = uuid.uuid4()
print("Generated UUID:", new_uuid)
UUIDs are commonly used to uniquely identify objects, transactions, or entities.
*args
is used in function definitions to allow the passing of a variable number of positional arguments. It collects additional arguments into a tuple.
def example_function(arg1, *args):
print("First argument:", arg1)
print("Additional arguments:", args)
example_function(1, 2, 3, 4)
In this example, args
would be a tuple containing (2, 3, 4)
.
**kwargs
allows the passing of a variable number of keyword arguments in a function. It collects additional keyword arguments into a dictionary.
def example_function(arg1, **kwargs):
print("First argument:", arg1)
print("Additional keyword arguments:", kwargs)
example_function(1, key1="value1", key2="value2")
In this example, kwargs
would be a dictionary containing {"key1": "value1", "key2": "value2"}
.
Arguments in Functions
When defining a function, you can use named arguments (also known as keyword arguments) to provide default values and improve readability:
def example_function(arg1, arg2=default_value):
print("arg1:", arg1)
print("arg2:", arg2)
example_function(1) # arg2 takes the default value
example_function(1, arg2="custom_value")
Named arguments allow you to call functions with a clear indication of what each argument represents.
Please feel free to explore this repo, and take any code or info based on your specific needs or project requirements. Happy coding!