pythonSandbox/python-Flask-Notes.txt at master · yaelBrown/pythonSandbox · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
Python Flask framework
  Flask is usually used as a restful API
  API - a program that takes in some data and gives back some other data, usually after processing it.
    For example, Twitter Search. Twitter search accepts data (the search parameters), processes it (finds the tweets that match those parameters), and sends data back (the tweets themselves).
    If you are a user of the Twitter Search API, you can send them the search parameters and you get back the tweets.
  REST - Representational State Transfer
    A way of thinking of how server responds to requests
    Returns resources
    Stateless - one request cannot depend on other requests
      Server only knows about the current request and not any previous requests
  Jinja - templating language

  https://github.com/schoolofcode-me/rest-api-sections/tree/master/section3

  pip install flask
    (pip3 or pip3.5 etc install flask)
    install flask
    recommended install in a virtual environment

    WSGI - Web Server Gateway Interface
      Python standard described in detail in PEP 3333
      describes how a web server communicates with web applications, and how web applications can be chained together to process one request

  (Add boilerplate from usefulPython/)

  https://www.youtube.com/watch?v=K5LBC3hLl8w
    Register blueprints

  python server.py
    http://localhost:5000/

  @app.route()
    by default are GET requests
    Need to add method=['POST'] in parameter for other verbs

  from flask import jsonify - similar to GSON and Jackson
    jsonify - creates json data for output.
      return jsonify({"output": "content"})
      json always returns double quotes never single quotes


  Flask-restful
    https://github.com/schoolofcode-me/rest-api-sections/tree/master/section4
    limited to only REST standard.

    pip freeze
      shows libraries currently installed and in use in current python environment
    pip install virtualenv
      tool used to create virtual environments
    virtualenv venv --python=python3.8
      will create a folder called venv and install python 3.8
    source venv/bin/activate [mac]
    ./venv/Scripts/activate.bat [win]
      activates virutal environment
    deactivate [mac]
    ./venv/Scripts/deactivate.bat [win]
      exits python virtual environment
    pip install flask-restful
      install flask-restful

    Api works with resources and each resource has to be a class
      You inherit Resource (package)

    No JSONify when using flask-restful

    HTTP status code: 201 = created
      202 = Accepted
        Will create later
      Using correct status code is important


  SQLAlchemy
    Create resources and models folder
      add __init__.py file in these folders

    @classmethod - annotation that is only used for the class.
      Not directed interacted with by the client

    Methods in a file should be separated by 1 line.
    Classes in a file should be separated by 2 lines.