Create app.py

app.py

@@ -0,0 +1,30 @@
+# app.py
+from flask import Flask, request, render_template
+import math
+
+app = Flask(__name__)
+
+@app.route('/')
+def index():
+    return render_template('index.html')
+
+@app.route('/calculate', methods=['POST'])
+def calculate():
+    voltage = float(request.form['voltage'])
+    current = float(request.form['current'])
+    real_power = float(request.form['power'])
+
+    apparent_power = voltage * current  # in VA
+    if apparent_power == 0:
+        reactive_power = 0
+    else:
+        reactive_power = math.sqrt(apparent_power**2 - real_power**2)  # in VAR
+
+    return render_template('index.html',
+                           voltage=voltage,
+                           current=current,
+                           real_power=real_power,
+                           reactive_power=round(reactive_power, 2))
+
+if __name__ == '__main__':
+    app.run(debug=True)