weekly-covid-average: new script

diff --git a/weekly-covid-average b/weekly-covid-average
new file mode 100755 (executable)
index 0000000..bbaf8dd
--- /dev/null
+++ b/weekly-covid-average
@@ -0,0 +1,67 @@
+#! /usr/bin/python3
+
+from argparse import ArgumentParser
+from email.message import EmailMessage
+import io
+import json
+from smtplib import SMTP
+import statistics
+
+import requests
+import toml
+
+
+def fetch_data():
+    # Fetch new case counts for Cambridgeshire.
+    data = requests.get(
+        "https://api.coronavirus.data.gov.uk/v1/data",
+        params={
+            "filters": "areaType=utla;areaName=Cambridgeshire",
+            "structure": json.dumps(
+                ["date", "newCasesBySpecimenDate"], separators=(",", ":")
+            ),
+        },
+    ).json()["data"]
+
+    # Skip the first three days of the response.  This seems to be what the
+    # website does, presumably because recent dates don't have reliable
+    # enough numbers yet.
+    data = data[3:]
+
+    last_week = data[:7]
+    mean = statistics.mean([new_cases for _, new_cases in last_week])
+    return last_week, mean
+
+
+def main():
+    parser = ArgumentParser()
+    parser.add_argument(
+        "--config", type=toml.load, default={},
+        help="Configuration file (TOML format)")
+    parser.add_argument("--email", action="store_true")
+    args = parser.parse_args()
+
+    last_week, mean = fetch_data()
+    formatted = io.StringIO()
+    print(
+        "Most recent week's worth of new cases in Cambridgeshire, "
+        "by specimen date:",
+        file=formatted)
+    print(file=formatted)
+    print(f"Mean: {mean:.1f}", file=formatted)
+    for date, new_cases in last_week:
+        print(f"{date}: {new_cases}", file=formatted)
+    if args.email and "email" in args.config:
+        new_cases_message = EmailMessage()
+        new_cases_message["From"] = args.config["email"]["from"]
+        new_cases_message["To"] = ", ".join(args.config["email"]["to_always"])
+        new_cases_message["Subject"] = f"Cambridgeshire case count: {mean:.1f}"
+        new_cases_message.set_content(formatted.getvalue())
+        with SMTP("localhost") as smtp:
+            smtp.send_message(new_cases_message)
+    else:
+        print(formatted.getvalue(), end="")
+
+
+if __name__ == "__main__":
+    main()