app.py

import gradio as gr
import pandas as pd
import plotly.express as px
from shapely.geometry import Point, Polygon

def load_csv(file):
    return pd.read_csv(file.name)

def update_dropdowns(df):
    return gr.Dropdown(choices=df.columns.tolist()), gr.Dropdown(choices=df.columns.tolist())

def create_plot(df, x_col, y_col):
    if df is None or x_col is None or y_col is None:
        return None
        
    fig = px.scatter(df, x=x_col, y=y_col, title=f"{x_col} vs {y_col}")
    fig.update_layout(dragmode='lasso')
    return fig

def find_points_in_polygon(selected_data, df, x_col, y_col):
    if not selected_data or not df.empty:
        return pd.DataFrame()
    
    # Get selected points from Plotly's lasso selection
    selected_points = selected_data['points']
    if not selected_points:
        return pd.DataFrame()
    
    # Extract coordinates of polygon vertices
    polygon_points = [(p['x'], p['y']) for p in selected_points]
    
    # Create polygon and check containment
    polygon = Polygon(polygon_points)
    mask = df.apply(lambda row: polygon.contains(Point(row[x_col], row[y_col])), axis=1)
    
    return df[mask]

with gr.Blocks() as demo:
    gr.Markdown("## Interactive CSV Explorer with Polygon Selection")
    
    df_state = gr.State(pd.DataFrame())
    x_col_state = gr.State()
    y_col_state = gr.State()
    
    with gr.Row():
        csv_upload = gr.File(label="Upload CSV", file_types=[".csv"])
        x_col = gr.Dropdown(label="X Column")
        y_col = gr.Dropdown(label="Y Column")
    
    plot = gr.Plot(label="Scatter Plot")
    results = gr.DataFrame(label="Selected Points")
    
    # Upload handling
    csv_upload.upload(
        load_csv,
        inputs=csv_upload,
        outputs=df_state
    ).then(
        update_dropdowns,
        inputs=df_state,
        outputs=[x_col, y_col]
    )
    
    # Plot updates
    x_col.change(
        create_plot,
        inputs=[df_state, x_col, y_col],
        outputs=plot
    ).then(
        lambda x: x,  # Store x_col in state
        inputs=x_col,
        outputs=x_col_state
    )
    
    y_col.change(
        create_plot,
        inputs=[df_state, x_col, y_col],
        outputs=plot
    ).then(
        lambda y: y,  # Store y_col in state
        inputs=y_col,
        outputs=y_col_state
    )
    
    # Selection handling
    plot.select(
        find_points_in_polygon,
        inputs=[gr.State(), df_state, x_col_state, y_col_state],
        outputs=results
    )

demo.launch()