Migrating to Quart

gentle_gnomes/pyproject.toml

@@ -8,15 +8,17 @@ packages = [ { include = "src" } ]
 
 [tool.poetry.dependencies]
 python = "^3.7"
-flask = "^1.0"
 python-dotenv = "^0.10.3"
-requests = "^2.22"
 scipy = "^1.3"
+aiohttp = "^3.5"
+quart = "^0.9.1"
+uvloop = "^0.12.2"
 
 [tool.poetry.dev-dependencies]
 pytest = "^4.6"
 coverage = "^4.5"
 flake8 = "^3.7"
+pytest-asyncio = "^0.10.0"
 pre-commit = "^1.17"
 flake8-bugbear = "^19.3"
 flake8-quotes = "^2.0"

gentle_gnomes/src/__init__.py

@@ -1,19 +1,25 @@
-from flask import Flask
+import uvloop
+from quart import Quart
 
 from . import azavea
 from . import view
 
+uvloop.install()
 
 def create_app(test_config=None):
-    app = Flask(__name__, instance_relative_config=True)
+    app = Quart(__name__, instance_relative_config=True)
     app.config.from_mapping(SECRET_KEY='dev')
+    app.config.from_pyfile('config.py', silent=True)
 
-    if test_config is None:
-        app.config.from_pyfile('config.py', silent=True)
-    else:
+    if test_config is not None:
         app.config.from_mapping(test_config)
 
+    app.register_blueprint(view.bp)
+
     app.azavea = azavea.Client(app.config['AZAVEA_TOKEN'])
 
-    app.register_blueprint(view.bp)
+    @app.teardown_appcontext
+    async def teardown(*args):
+        await app.azavea.teardown()
+
     return app

gentle_gnomes/src/azavea.py

@@ -1,6 +1,6 @@
+import aiohttp
 import typing as t
-
-import requests
+import asyncio as aio
 
 BASE_URL = 'https://app.climate.azavea.com/api'
 
@@ -17,23 +17,31 @@ def __str__(self):
 class Client:
     """Client for interacting with the Azavea Climate API."""
 
+    # Wait for async event loop to instanstiate
+    session: aiohttp.ClientSession = None
+
     def __init__(self, token: str):
-        self.session = requests.Session()
-        self.session.headers = {'Authorization': f'Token {token}'}
+        self.headers = {'Authorization': f'Token {token}'}
+
+    async def _get(self, endpoint: str, **kwargs) -> t.Union[t.Dict, t.List]:
+        if self.session is None:
+            self.session = aiohttp.ClientSession(headers=self.headers)
+
+        async with self.session.get(BASE_URL + endpoint, **kwargs) as response:
+            return await response.json()
 
-    def _get(self, endpoint: str, **kwargs) -> t.Union[t.Dict, t.List]:
-        response = self.session.get(BASE_URL + endpoint, ** kwargs)
-        response.raise_for_status()
+    async def teardown(self):
+        if self.session is not None:
+            await self.session.close()
 
-        return response.json()
 
-    def get_cities(self, **kwargs) -> t.Iterator[City]:
+    async def get_cities(self, **kwargs) -> t.Iterator[City]:
         """Return all available cities."""
         params = {'page': 1}
         params.update(kwargs.get('params', {}))
 
         while True:
-            cities = self._get('/city', params=params, **kwargs)
+            cities = await self._get('/city', params=params, **kwargs)
 
             if not cities.get('next'):
                 break
@@ -43,7 +51,7 @@ def get_cities(self, **kwargs) -> t.Iterator[City]:
             for city in cities['features']:
                 yield City(city['properties']['name'], city['properties']['admin'], city['id'])
 
-    def get_nearest_city(
+    async def get_nearest_city(
         self,
         lat: float,
         lon: float,
@@ -57,24 +65,24 @@ def get_nearest_city(
             'limit': limit,
         }
 
-        cities = self._get('/city/nearest', params=params, **kwargs)
+        cities = await self._get('/city/nearest', params=params, **kwargs)
 
         if cities['count'] > 0:
             city = cities['features'][0]
             return City(city['properties']['name'], city['properties']['admin'], city['id'])
 
-    def get_scenarios(self, **kwargs) -> t.List:
+    async def get_scenarios(self, **kwargs) -> t.List:
         """Return all available scenarios."""
-        return self._get('/scenario', **kwargs)
+        return await self._get('/scenario', **kwargs)
 
-    def get_indicators(self, **kwargs) -> t.Dict:
+    async def get_indicators(self, **kwargs) -> t.Dict:
         """Return the full list of indicators."""
-        return self._get('/indicator', **kwargs)
+        return await self._get('/indicator', **kwargs)
 
-    def get_indicator_details(self, indicator: str, **kwargs) -> t.Dict:
+    async def get_indicator_details(self, indicator: str, **kwargs) -> t.Dict:
         """Return the description and parameters of a specified indicator."""
-        return self._get(f'/indicator/{indicator}', **kwargs)
+        return await self._get(f'/indicator/{indicator}', **kwargs)
 
-    def get_indicator_data(self, city: int, scenario: str, indicator: str, **kwargs) -> t.Dict:
+    async def get_indicator_data(self, city: int, scenario: str, indicator: str, **kwargs) -> t.Dict:
         """Return derived climate indicator data for the requested indicator."""
-        return self._get(f'/climate-data/{city}/{scenario}/indicator/{indicator}', **kwargs)
+        return await self._get(f'/climate-data/{city}/{scenario}/indicator/{indicator}', **kwargs)

gentle_gnomes/src/indicator.py

@@ -3,7 +3,7 @@
 from typing import Tuple
 
 import numpy as np
-from flask import current_app as app
+from quart import current_app as app
 from scipy import stats
 
 from .azavea import City
@@ -19,14 +19,13 @@ class Indicator:
     def __init__(self, name: str, city: City):
         self.name = name
         self.city = city
-        self._populate_data()
 
-    def _populate_data(self):
+    async def _populate_data(self):
         items = []
         count = 0
 
         for scenario in ('historical', 'RCP85'):
-            response = app.azavea.get_indicator_data(self.city.id, scenario, self.name)
+            response = await app.azavea.get_indicator_data(self.city.id, scenario, self.name)
             self.label = response['indicator']['label']
             self.description = response['indicator']['description']
             self.units = response['units']
@@ -50,13 +49,14 @@ def _calc_slope(x: np.ndarray, y: np.ndarray) -> float:
         return slope
 
 
-def get_top_indicators(city: City, n: int = 5) -> Tuple[Indicator, ...]:
+async def get_top_indicators(city: City, n: int = 5) -> Tuple[Indicator, ...]:
     """Return the top n indicators with the highest rate of change."""
     rates = Counter()
     indicators = {}
 
     for name in INDICATORS:
         indicator = Indicator(name, city)
+        await self._populate_data()
 
         rates[name] = indicator.rate
         indicators[name] = indicator

gentle_gnomes/src/view.py

@@ -1,32 +1,33 @@
 import json
 
-import flask
-from flask import current_app as app
-from flask import render_template
+import quart
+from quart import current_app as app
+from quart import render_template
 
 from . import indicator
 
-bp = flask.Blueprint('view', __name__, url_prefix='/')
+bp = quart.Blueprint('view', __name__, url_prefix='/')
 
 
 @bp.route('/')
-def index():
-    return render_template('view/index.html')
+async def index():
+    return await render_template('view/index.html')
 
 
 @bp.route('/search', methods=['POST'])
-def search():
+async def search():
     try:
-        location = json.loads(flask.request.form['location'])
+        form = await quart.request.form
+        location = json.loads(form['location'])
         latitude = location['lat']
         longitude = location['lng']
     except (json.JSONDecodeError, KeyError):
         return render_template('view/results.html')
 
-    city = app.azavea.get_nearest_city(latitude, longitude)
+    city = await app.azavea.get_nearest_city(latitude, longitude)
     if city:
         with app.app_context():
-            results = indicator.get_top_indicators(city)
+            results = await indicator.get_top_indicators(city)
     else:
         results = None
 

gentle_gnomes/tests/conftest.py

@@ -1,6 +1,7 @@
 import pytest
 
 from src import create_app
+from src.azavea import Client
 
 
 @pytest.fixture
@@ -17,3 +18,8 @@ def client(app):
 @pytest.fixture
 def runner(app):
     return app.test_cli_runner()
+
+
+@pytest.fixture
+def azavea(app):
+    return Client(app.config['AZAVEA_TOKEN'])

gentle_gnomes/tests/test_azavea.py

@@ -0,0 +1,6 @@
+import pytest
+
+
+@pytest.mark.asyncio
+async def test_request_data_exists(azavea):
+    assert await azavea.get_indicators()

gentle_gnomes/tests/test_view.py

@@ -1,2 +1,7 @@
-def test_index_response_200(client):
-    assert client.get('/').status_code == 200
+import pytest
+
+
+@pytest.mark.asyncio
+async def test_index_response_200(client):
+    res = await client.get('/')
+    assert res.status_code == 200