Code Editor for app.py

import streamlit as st
import pandas as pd
from io import StringIO

st.title("CSV File Editor")

# Upload file
uploaded_file = st.file_uploader("Upload your CSV file", type=['csv'])

if uploaded_file is not None:
    # Read the CSV file
    df = pd.read_csv(uploaded_file)
    
    # Show original data
    st.subheader("Original Data")
    st.dataframe(df)
    
    # Options
    option = st.selectbox(
        "Choose operation",
        ["Reorder columns", "Add new column"]
    )
    
    if option == "Reorder columns":
        st.subheader("Reorder Columns")
        column_order = st.multiselect(
            "Drag to reorder columns",
            df.columns.tolist(),
            default=df.columns.tolist()
        )
        
        if len(column_order) == len(df.columns):
            df = df[column_order]
        else:
            st.warning("Please select all columns")
            
    elif option == "Add new column":
        st.subheader("Add New Column")
        new_column_name = st.text_input("Enter new column name")
        new_column_value = st.text_input("Enter value for all rows")
        
        if new_column_name and new_column_value:
            df[new_column_name] = new_column_value
    
    # Show modified data
    st.subheader("Modified Data")
    st.dataframe(df)
    
    # Download button
    csv = df.to_csv(index=False)
    st.download_button(
        label="Download modified CSV",
        data=csv,
        file_name="modified.csv",
        mime="text/csv"
    )