Code Editor for app.py

import streamlit as st
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import RectangleSelector
from datetime import datetime, timedelta

# Initialize session state for storing selections
if 'selected_ranges' not in st.session_state:
    st.session_state.selected_ranges = pd.DataFrame(columns=['Start Date', 'End Date'])

# Generate sample datetime data
def generate_sample_data():
    dates = pd.date_range(start='2023-01-01', end='2023-12-31', freq='D')
    values = np.random.randn(len(dates)).cumsum()
    return pd.DataFrame({'Date': dates, 'Value': values})

# Function to handle selection
def line_select_callback(eclick, erelease):
    if 'temp_selection' not in st.session_state:
        st.session_state.temp_selection = {}
    
    x1, x2 = sorted([eclick.xdata, erelease.xdata])
    st.session_state.temp_selection = {
        'start': matplotlib_num_to_datetime(x1),
        'end': matplotlib_num_to_datetime(x2)
    }

# Convert matplotlib date numbers to datetime
def matplotlib_num_to_datetime(x):
    return datetime.fromordinal(int(x)) + timedelta(days=x%1)

# Create the main plot
def create_plot(df):
    fig, ax = plt.subplots(figsize=(10, 6))
    ax.plot(df['Date'], df['Value'])
    ax.set_title('Interactive Date Range Selector')
    ax.set_xlabel('Date')
    ax.set_ylabel('Value')
    
    # Add the rectangle selector
    rect_selector = RectangleSelector(
        ax, line_select_callback,
        useblit=True,
        button=[1],  # Left mouse button only
        minspanx=5,  # Minimum pixel distance to start selection
        spancoords='pixels',
        interactive=True
    )
    
    return fig

# Main app
st.title('Interactive Date Range Selector')

# Generate or get data
df = generate_sample_data()

# Create and display the plot
fig = create_plot(df)
plot_placeholder = st.pyplot(fig)

# Add button to store selection
if st.button('Store Selected Range'):
    if 'temp_selection' in st.session_state and st.session_state.temp_selection:
        new_range = pd.DataFrame({
            'Start Date': [st.session_state.temp_selection['start']],
            'End Date': [st.session_state.temp_selection['end']]
        })
        st.session_state.selected_ranges = pd.concat([
            st.session_state.selected_ranges,
            new_range
        ], ignore_index=True)
        st.session_state.temp_selection = {}  # Clear the temporary selection
        st.rerun()

# Display stored ranges
if not st.session_state.selected_ranges.empty:
    st.subheader('Stored Date Ranges')
    st.dataframe(st.session_state.selected_ranges)