Pybites Platform

Back

Return an html response

Pybites

Level: Intermediate (score: 3)

You use FastAPI primarily to build APIs, but it can also be used as a web framework (although we think Django is a better option for this).

You can install Jinja2 and return a template response as shown here.

However on our platform we work with single test and exercise files so in this Bite you will return an HTMLResponse with embedded HTML (docs). The effect will be the same though: the food log of a user in a nice html table!

Food	Added	Servings	Calories (kcal)
egg	2022-03-13 11:02:37.500968	1.5 x piece	117.0
oatmeal	2022-03-13 11:02:37.500968	2.0 x 100 grams	672.0

We provided the show_foods_for_user endpoint stub, add the logic to build up the HTML for the response. For your convenience we already added some template constants you can use: HTML_TEMPLATE and TABLE_ROW.

Here is what the final HTML response would look like as per the tests:

<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Food log for Julian</title>
</head>
<body>
    <table>
        <thead>
            <th>Food</th>
            <th>Added</th>
            <th>Servings</th>
            <th>Calories (kcal)</th>
        </thead>
        <tbody>
              <tr>
                  <td>egg</td>
                  <td>2022-03-13 11:02:37.500968</td>
                  <td>1.5 x piece</td>
                  <td>117.0</td>
              </tr>
              <tr>
                  <td>oatmeal</td>
                  <td>2022-03-13 11:02:37.500968</td>
                  <td>2.0 x 100 grams</td>
                  <td>672.0</td>
              </tr>
        </tbody>
    </table>
</body>
</html>

Good luck and in the next and final FastAPI Bite we will add authentication to the API.

FastAPI

Code
Tests

from datetime import datetime
from typing import Any, Dict, List

from fastapi import FastAPI, Request
from fastapi.responses import HTMLResponse
from passlib.context import CryptContext
from pydantic import BaseModel

# https://fastapi.tiangolo.com/tutorial/security/oauth2-jwt/
# We'll export authentication further in a later Bite
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

def get_password_hash(password):
    return pwd_context.hash(password)

class Food(BaseModel):
    id: int
    name: str
    serving_size: str
    kcal_per_serving: int
    protein_grams: float
    fibre_grams: float = 0

class User(BaseModel):
    id: int
    username: str
    password: str

def __init__(self, **data: Any):
        data["password"] = get_password_hash(data["password"])
        super().__init__(**data)

class FoodEntry(BaseModel):
    id: int
    user: User
    food: Food
    date_added: datetime = datetime.now()
    number_servings: float

@property
    def total_calories(self):
        return self.food.kcal_per_serving * self.number_servings

app = FastAPI()

food_log: Dict[int, FoodEntry] = {}

HTML_TEMPLATE = """<!doctype html>

<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Food log for {username}</title>
</head>

<body>
    <table>
        <thead>
            <th>Food</th>
            <th>Added</th>
            <th>Servings</th>
            <th>Calories (kcal)</th>
        </thead>
        <tbody>
            {table_rows}
        </tbody>
    </table>

</body>
</html>"""
TABLE_ROW = """<tr>
    <td>{food_name}</td>
    <td>{date_added}</td>
    <td>{number_servings} x {serving_size}</td>
    <td>{total_calories}</td>
</tr>"""

@app.post("/", status_code=201)
async def create_food_entry(entry: FoodEntry):
    """Previous Bite and used in test"""
    food_log[entry.id] = entry
    return entry

@app.get("/{username}", response_class=HTMLResponse)
async def show_foods_for_user(request: Request, username: str):
    # 1. extract foods for user using the food_log dict
    # 2. build up the embedded html string
    # 3. return an HTMLResponse (with the html content and status code 200)
    pass

​x
 
from datetime import datetime
from typing import Any, Dict, List
​
from fastapi import FastAPI, Request
from fastapi.responses import HTMLResponse
from passlib.context import CryptContext
from pydantic import BaseModel
​
# https://fastapi.tiangolo.com/tutorial/security/oauth2-jwt/
# We'll export authentication further in a later Bite
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
​
​
def get_password_hash(password):
    return pwd_context.hash(password)
​
​
class Food(BaseModel):
    id: int
    name: str
    serving_size: str
    kcal_per_serving: int
    protein_grams: float
    fibre_grams: float = 0
​
​
class User(BaseModel):
    id: int
    username: str
    password: str
​
    def __init__(self, **data: Any):
        data["password"] = get_password_hash(data["password"])
        super().__init__(**data)
​
​
class FoodEntry(BaseModel):
    id: int
    user: User
    food: Food
    date_added: datetime = datetime.now()
    number_servings: float
​
    @property
    def total_calories(self):
        return self.food.kcal_per_serving * self.number_servings
​
​
app = FastAPI()
​
food_log: Dict[int, FoodEntry] = {}
​
HTML_TEMPLATE = """<!doctype html>
​
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Food log for {username}</title>
</head>
​
<body>
    <table>
        <thead>
            <th>Food</th>
            <th>Added</th>
            <th>Servings</th>
            <th>Calories (kcal)</th>
        </thead>
        <tbody>
            {table_rows}
        </tbody>
    </table>
​
</body>
</html>"""
TABLE_ROW = """<tr>
    <td>{food_name}</td>
    <td>{date_added}</td>
    <td>{number_servings} x {serving_size}</td>
    <td>{total_calories}</td>
</tr>"""
​
​
@app.post("/", status_code=201)
async def create_food_entry(entry: FoodEntry):
    """Previous Bite and used in test"""
    food_log[entry.id] = entry
    return entry
​
​
@app.get("/{username}", response_class=HTMLResponse)
async def show_foods_for_user(request: Request, username: str):
    # 1. extract foods for user using the food_log dict
    # 2. build up the embedded html string
    # 3. return an HTMLResponse (with the html content and status code 200)
    pass

from datetime import datetime

import pytest
from bs4 import BeautifulSoup
from fastapi.testclient import TestClient

from app import app, food_log, pwd_context

LAME_PASSWORD = "1234"  # noqa S105

# also from https://fastapi.tiangolo.com/tutorial/security/oauth2-jwt/
def _verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)

@pytest.fixture
def client():
    client = TestClient(app)
    return client

@pytest.fixture
def user():
    user = dict(id=1, username="Julian", password=LAME_PASSWORD)
    return user

@pytest.fixture
def food1():
    food = dict(
        id=1,
        name="egg",
        serving_size="piece",
        kcal_per_serving=78,
        protein_grams=6.2,
        fibre_grams=0,
    )
    return food

@pytest.fixture
def food2():
    food = dict(
        id=2,
        name="oatmeal",
        serving_size="100 grams",
        kcal_per_serving=336,
        protein_grams=13.2,
        fibre_grams=10.1,
    )
    return food

@pytest.fixture
def food_entry1(user, food1):
    payload = dict(id=1, user=user, food=food1, number_servings=1.5)
    yield payload
    del food_log[1]

@pytest.fixture
def food_entry2(user, food2):
    payload = dict(id=2, user=user, food=food2, number_servings=2)
    yield payload
    del food_log[2]

@pytest.fixture(autouse=True)
def create_food_entries(client, food_entry1, food_entry2):
    client.post("/", json=food_entry1)
    client.post("/", json=food_entry2)

def test_show_foods_for_user(client):
    resp = client.get("/Julian")
    assert resp.status_code == 200
    try:
        soup = BeautifulSoup(resp.text, "html.parser")
    except Exception as exc:
        pytest.fail(f"Could not make soup object for testing, exception: {exc}")

assert soup.title.text == "Food log for Julian"

assert len(soup.findAll("tr")) == 2
    tds = soup.findAll("td")
    assert len(tds) == 8

# datetimes change and freezegun did not work so best we can do is assert type
    dt1, dt2 = tds.pop(1).text, tds.pop(4).text
    for dt in (dt1, dt2):
        isinstance(datetime.strptime(dt, "%Y-%m-%d %H:%M:%S.%f"), datetime)

# remaining cells are plain text
    text_cells = [td.text for td in tds]
    assert text_cells == [
        "egg",
        "1.5 x piece",
        "117.0",
        "oatmeal",
        "2.0 x 100 grams",
        "672.0",
    ]