Introduction to rest using flask

Introduction to rest using flask

• 1.
  Introduction to REST
 andits implementation using Flask in Python. Murtadha Bazli Tukimat
 Developer/Founder at Wekanta
 bazli@wekanta.com Wekanta
• 2.
  REST ๏ Background ๏ HTTPMethod ๏ Path Format ๏ Response Code Wekanta
• 3.
  What is REST? •REpresentational State Transfer (REST) • An architectural style for standards communication between computer system over the web • RESTful application is reliable, quick and scalable. Wekanta Request Response Client Server
• 4.
  HTTP Method • GET– retrieve a specific resource (by id) or a collection of resources. Most common method. • POST – create a new resource once. • PUT – similar to POST but might overwriting old values multiple times due to lost connection. • DELETE – remove a specific resource by id • Essential for Create, Read, Update and Delete operations (CRUD) Wekanta
• 5.
  Path Format • Shouldbe designed to help client know what is going on. • First path should be plural form such as products, customers, books etc. Wekanta # Example http://api.webapp.com/products/engineering/20 IDCollection CategoryBase Path
• 6.
  Response Code • GET– return 200 (OK) • POST – return 201 (Created) • PUT – return 200 (OK) • DELETE – return 204 (if document not exist) Wekanta Read it more here … https://goo.gl/gfFxsu
• 7.
  FLASK ๏ Background ๏ HelloWorld! ๏ HTTP Method ๏ Route ๏ Variable ๏ Logging ๏ Try it! Wekanta
• 8.
  What is Flask? •Micro web framework written in Python • Lightweight and little dependency • Simple to get started • Built-in server for debugger Wekanta Read it more here … https://goo.gl/5zocHd
• 9.
  Hello World! #!/usr/local/bin/python3
 
 from flaskimport Flask
 app = Flask(__name__) @app.route('/') # bind 127.0.0.1:5000/ to route '/'
 def hello():
 return "Hello World!" 
 if __name__ == '__main__':
 app.run() # run local server at port 5000 Wekanta
• 10.
  HTTP Method Wekanta from flaskimport request @app.route('/hello', methods=['GET', 'POST'])
 def hello():
 if request.method == 'POST':
 return "Do insert here…" • Default access for GET request • Common methods GET, HEAD, POST, PUT, DELETE, OPTIONS • Return 405 if method request is not allowed
• 11.
  Route Wekanta @app.route('/hello')
 def hello():
 return "HelloWorld!" • route( ) decorator used to bind URL to a method • Take care of plural and singular in route (books or book?) • Route name must be in lowercase
• 12.
  Variable Wekanta @app.route('/products/<int:doc_id>')
 def get_products(doc_id):
 return "Products# %d Informations." % doc_id • <your_variable_name> here • Accept integer and floating point value • Unmet variable type will return status 404
• 13.
  Logging Wekanta if __name__ =='__main__':
 handler = RotatingFileHandler(
 'foo.log', maxBytes=1000000, backupCount=5)
 
 log = logging.getLogger('werkzeug')
 log.addHandler(handler) # save to log file
 app.logger.addHandler(handler) # see in terminal
 app.run() • FileHandler vs. RotatingFileHandler • Optional log levels for Debug, Info, Warning and Error • Split log file for easy debugging
• 14.
  Try It! Wekanta # DownloadLink
 https://goo.gl/aVtQJd
• 15.
  Q&A Wekanta