Create app.py

app.py

@@ -0,0 +1,43 @@
+from flask import Flask, render_template, request
+import os
+
+app = Flask(__name__)
+
+FILE_NAME = "data.txt"
+
+# create file if not exists
+if not os.path.exists(FILE_NAME):
+    open(FILE_NAME, "w").close()
+
+
+@app.route("/")
+def home():
+    return render_template("index.html")
+
+
+@app.route("/operate", methods=["POST"])
+def operate():
+
+    text = request.form.get("text")
+    operation = request.form.get("operation")
+
+    if operation == "write":
+        with open(FILE_NAME, "w") as f:
+            f.write(text + "\n")
+
+    elif operation == "append":
+        with open(FILE_NAME, "a") as f:
+            f.write(text + "\n")
+
+    elif operation == "read":
+        with open(FILE_NAME, "r") as f:
+            text = f.read()
+
+    else:
+        text = "Invalid operation"
+
+    return render_template("index.html", result=text)
+
+
+if __name__ == "__main__":
+    app.run(host="0.0.0.0", port=7860)