Fast Flask Dev For Big Codebases

Transcript

1. Fast Flask dev for Big Codebases
2. ssslides
5. Python Mauritius UserGroup (pymug) More info: mscc.mu/python-mauritius-usergroup-pymug/ Why Where codes github.com/pymug share events twitter.com/pymugdotcom ping professionals linkedin.com/company/pymug all info pymug.com tell friends by like facebook.com/pymug 5
6. Abdur-Rahmaan Janhangeer Help people get into OpenSource People hire me to work on Python projects www.compileralchemy.com 6
7. Fav foreign (https://metabob.com) World's most advanced code analysis tool? Fav local (https://oceandba.com) 7
8. Fast Flask dev for Big Codebases 8
9. The Flask Story 9
10. Begin new project 10
11. Code features 11
12. Deploy 12
13. Refine Deploy 13
14. TEST AND PROD ENV DIFFERENT 14
15. USE CONFIGURATION PROFILES 15
16. ADD APP FACTORY 16
17. APP BREAKING 17
18. WRITE TESTS 18
19. CODE DISORGANISED 19
20. ORGANISE CODEBASE 20
21. TESTS ARE BORING 21
22. WRITE FIXTURES, WRITE SCHEMAS 22
23. I HAVE TO START A NEW PROJECT 23
24. HAVE A TEMPLATE 24
25. NOW I HAVE TO USE APIS 25
26. INTEGRATE API-FRAMEWORK 26
27. pulls some more hair 27
28. I WANT TO INTEGRATE CELERY 28
29. INTEGRATE CELERY 29
30. dev left ... 30
31. THE NEW INTERN DOES NOT UNDERSTAND ANYTHING 31
32. WRITE DOCS!!! 32
33. You need something that flies in all weather 33
34. The Application Factory 34
35. def create_app(app_name): app = Flask(app_name) return app 35
36. Configuration Profiles 36
37. class Config: TESTING = False class ProductionConfig(Config): FAV_FLOWER = 'rose' class DevelopmentConfig(Config): FAV_FLOWER = 'sunflower' class TestingConfig(Config): FAV_FLOWER = 'moonlight petal' TESTING = True 37
38. from config import ProductionConfig from config import DevelopmentConfig from config import TestingConfig profiles = { 'development': DevelopmentConfig(), 'production': ProductionConfig(), 'testing': TestingConfig() } def create_app(profile): app = Flask(__name__) app.config.from_object(profiles[profile]) return app 38
39. Tests 39
40. Use Pytest Use class-based testing Define fixtures for common actions e.g. logout/login 40
41. Docs 41
42. Use Sphinx from the start 42
43. Separate Initialisations From The Factory 43
44. Use a file for initialisations Reduces import errors to a max 44
45. app.py init.py 45
46. init.py db = SQLAlchemy() ma = Marshmallow() login_manager = LoginManager() migrate = Migrate() mail = Mail() 46
47. from init import mail def create_app(...): app = ... mail.init_app(app) in other files: from init import db 47
48. Use modules for everything!!! 48
49. app.py module1/ module2/ module3/ 49
50. app.py modules/ module1/ module2/ 50
51. module1/ templates/ static/ test/ models.py forms.py view.py etc etc 51
52. Use flask to simplify your life 52
53. @app.cli.command("jump", short_help="skip something") def jump(): # do something return 0 # cli flask jump 53
54. Automate blueprint registration 54
55. 1. name each blueprint: foldername_blueprint 2. In app.py # pseudocode for folder in modules: blueprint = import(f'modules.{folder}.view.{folder}_blueprint') app.register(blueprint) 55
56. Automate module creation 56
57. # pseudocode def createmodule(name): mkdir(folder) touch(folder/models.py) touch(folder/) ... # cli flask createmodule apple 57
58. Form help yourself 58
59. Use flask-wtf Use wtforms-alchemy class ConfForm(ModelForm): class Meta: model = Conf 59
60. Contain static in module, implement collecstatic 60
61. app.py static/ # served from here in production modules/ m1/ static/ file.png m2/ static/ file.png collectstatic just collects all assets in all modules and add it under app.py static/ modules/ m1/ file.png m2/ file.png 61
62. define function serve_asset(module, resource_path) e.g. serve_asset('m1', 'file.png') if mode is dev serve from /modules/m1/static/file.png i.e /modules/module_name/m1/static/path/to/file.png if mode is prod serve from /static/modules/m1/file.png (assumes collecstatic run before) i.e /static/modules/module_name/path/to/file.png 62
63. What for celery? 63
64. app.py init.py celery_app.py modules/ m1/ task.py 64
65. init.py celery = Celery( __name__, broker=BaseConfig.CELERY_BROKER_URL, backend=BaseConfig.CELERY_RESULT_BACKEND, ) 65
66. app.py from init import celery def init_celery(app=None): app = create_app(os.getenv("FLASK_ENV", "")) app = app or create_app() celery.conf.update(app.config) class ContextTask(celery.Task): """Make celery tasks work with Flask app context""" def __call__(self, *args, **kwargs): with app.app_context(): return self.run(*args, **kwargs) celery.Task = ContextTask return celery 66
67. celery_app.py from app import init_celery celery = init_celery() 67
68. modules/m1/task.py from init import celery @celery.task(name="do something", bind=True) def task_do_something(self): 68
69. What for flask-restx? 69
70. modules/ app.py init.py api_util.py 70
71. init.py api = Api( version="1.0", title="MVP Data", description="Backend Part", authorizations=authorizations, ) 71
72. api_util.py # from modules.some.api import some_ns from modules.some2.api import some2_ns # ns: namespace from init import api_v1 api_v = api_v1 # /api/v1 def add_api(api): api.add_namespace(some_ns, path=api_v + "/someapi") api.add_namespace(some2_ns, path=api_v + "/someapi2") 72
73. app.py from init import api from api_util import add_api def create_app(...): app = ... api.init_app(app) add_api(api) 73
74. Migrations to the next level 74
75. # make flask-migrate auto detect models for folder in modules: import(f'modules.{folder}.models.py') 75
76. Modular migration ideas: make flask_migrate or alembic load only specific classes 76
77. Reuse base 77
78. Use cookiecutter cookiecutter <url> Keep modules and init.py empty 78
79. The ongoing conclusion: 79
80. https://github.com/shopyo/shopyo Star it to show support! 80
81. Why not use Django? Because Flask 81
88. And, that's what shopyo is! 88
89. Like it? Appreciate a mail at: arj.python[@]gmail[.]com Means a lot to me! 89