# This program creates and displays a temperature database
# with options to insert, update, and delete records.
#
# Assumes Redis is installed locally. If you have Redis running
# separately (such as in a Docker container), replace localhost below
# with your Redis server's IP address.
#
# References:
# https://en.wikibooks.org/wiki/Python_Programming
# https://realpython.com/python-redis/
import flask
import redis as redis_lib
app = flask.Flask(__name__)
HOST = "localhost"
DATABASE = 0
FORM = """
<h1>Temperature Data Entry</h1>
<p>Enter country and temperature. Enter again to update.</p>
<p>Enter country without temperature to delete.</p>
<form method="POST">
<p><label for="country">Country:</label>
<input type="text" id="country" name="country" required></p>
<p><label for="stop">Temperature:</label>
<input type="text" id="temperature" name="temperature"></p>
<p><input type="submit" name="submit" value="Submit"></p>
</form>
<hr>
"""
@app.route('/', methods=["GET"])
def root_get():
try:
return FORM + get_data()
except Exception as exception:
return exception
@app.route('/', methods=["POST"])
def root_post():
try:
country = flask.request.form["country"].strip()
temperature = flask.request.form["temperature"].strip()
if not country_exists(country):
insert_country(country, temperature)
elif temperature != "":
update_country(country, temperature)
else:
delete_country(country)
return FORM + get_data()
except Exception as exception:
return exception
def get_data():
redis = redis_lib.Redis(host=HOST, db=DATABASE)
result = "<table><tr><th>Country</th>"
result += "<th>Temperature</th></tr>"
countries = redis.keys()
countries.sort()
for country in countries:
temperature = redis.get(country)
result += f"<tr><td>{country.decode()}</td>"
result += f"<td>{temperature.decode()}</td></tr>"
result += "</table>"
return result
def country_exists(country):
redis = redis_lib.Redis(host=HOST, db=DATABASE)
return bool(redis.exists(country))
def insert_country(country, temperature):
redis = redis_lib.Redis(host=HOST, db=DATABASE)
redis.set(country, temperature)
def update_country(country, temperature):
redis = redis_lib.Redis(host=HOST, db=DATABASE)
redis.set(country, temperature)
def delete_country(country):
redis = redis_lib.Redis(host=HOST, db=DATABASE)
redis.delete(country)
if __name__ == "__main__":
app.run(host='0.0.0.0', port=5000)
