Update app.py

app.py

@@ -1,32 +1,22 @@
 import streamlit as st
-import numpy as np
-import pandas as pd
-import altair as alt
 
-st.write('Hello World')
-
-st.header('button')
-
-if st.button('Say Hello'):
-    st.write('Why hello there')
-else:
-    st.write('Goodbye')
-
-
-st.header('st.write')
-
-st.write('Hello World')
-st.write(1234)
-
-df = pd.DataFrame({'first column':[1, 2, 3, 4], 'second column': [10, 20, 30, 40]})
-st.write(df)
-
-df2 =  pd.DataFrame(
-     np.random.randn(200, 3),
-     columns=['a', 'b', 'c'])
-st.write(df2.head(5))
-c = alt.Chart(df2).mark_circle().encode(
-     x='a', y='b', size='c', color='c', tooltip=['a', 'b', 'c'])
-st.write(c)
-
-st.latex(r'N_t = \frac{1}{10}')
+st.title("Calculator")
+
+col1, col2, col3 = st.columns(3)
+with col1:
+    a = st.number_input("First number", value=1.0)
+with col2:
+    b = st.number_input("Second number", value=2.0)
+with col3:
+    operation = st.selectbox("Choose the operation", ["+", "-", "*", "/"])
+if operation == "+":
+    st.write(a, "+", b, "=", a + b)
+elif operation == "-":
+    st.write(a, "-", b, "=", a - b)
+elif operation == "*":
+    st.write(a, "*", b, "=", a * b)
+elif operation == "/":
+    if b == 0:
+        st.warning("Divided by zero")
+    else:
+        st.write(a, "/", b, "=", a / b)