Layout and Containers

def container() -> DeltaGenerator:
    """
    Create an invisible container for grouping elements.
    
    Returns:
    DeltaGenerator: Container object for adding elements
    """

def empty() -> DeltaGenerator:
    """
    Create a placeholder container that can be filled later.
    
    Returns:
    DeltaGenerator: Empty container that can be populated programmatically
    """

import streamlit as st

# Container for grouping related content
with st.container():
    st.write("This content is in a container")
    st.button("Container button")

# Empty placeholder that can be filled later
placeholder = st.empty()

# Later in the code, fill the placeholder
placeholder.text("This text was added to the placeholder!")

def columns(spec, gap: str = "small") -> List[DeltaGenerator]:
    """
    Create a set of columns for side-by-side layout.
    
    Parameters:
    - spec: Number of columns (int) or list of column widths
    - gap: Gap size between columns ("small", "medium", "large")
    
    Returns:
    List[DeltaGenerator]: List of column containers
    """

import streamlit as st

# Equal width columns
col1, col2, col3 = st.columns(3)

with col1:
    st.header("Column 1")
    st.write("Content for first column")

with col2:
    st.header("Column 2")
    st.write("Content for second column")

with col3:
    st.header("Column 3")
    st.write("Content for third column")

# Custom width columns (ratios)
left_col, middle_col, right_col = st.columns([1, 2, 1])

with left_col:
    st.write("Narrow left")

with middle_col:
    st.write("Wide middle column")

with right_col:
    st.write("Narrow right")

# Large gap between columns
col_a, col_b = st.columns(2, gap="large")

with col_a:
    st.metric("Revenue", "$1.2M")

with col_b:
    st.metric("Users", "1,234")

def tabs(tab_labels: List[str]) -> List[DeltaGenerator]:
    """
    Create a tabbed interface.
    
    Parameters:
    - tab_labels: List of tab names/labels
    
    Returns:
    List[DeltaGenerator]: List of tab containers
    """

import streamlit as st
import pandas as pd
import numpy as np

# Create tabs
tab1, tab2, tab3 = st.tabs(["Data", "Charts", "Settings"])

with tab1:
    st.header("Data View")
    data = pd.DataFrame(np.random.randn(10, 3), columns=["A", "B", "C"])
    st.dataframe(data)

with tab2:
    st.header("Charts View")
    st.line_chart(data)
    st.bar_chart(data)

with tab3:
    st.header("Settings")
    st.selectbox("Theme", ["Light", "Dark"])
    st.checkbox("Enable notifications")

def expander(label: str, expanded: bool = False) -> DeltaGenerator:
    """
    Create an expandable/collapsible container.
    
    Parameters:
    - label: Text displayed on the expander header
    - expanded: Whether the expander is initially expanded
    
    Returns:
    DeltaGenerator: Expandable container
    """

import streamlit as st

# Basic expander
with st.expander("See explanation"):
    st.write("""
        This is a detailed explanation that is hidden by default.
        Users can click to expand and see this content.
    """)

# Initially expanded expander
with st.expander("Configuration Options", expanded=True):
    st.slider("Temperature", 0, 100, 50)
    st.selectbox("Model", ["GPT-3", "GPT-4"])

# Multiple expanders for organized content
with st.expander("📊 Data Analysis"):
    st.write("Data analysis content here")
    st.line_chart([1, 2, 3, 4, 5])

with st.expander("🔧 Settings"):
    st.checkbox("Debug mode")
    st.number_input("Batch size", value=32)

with st.expander("ℹ️ Help & Documentation"):
    st.markdown("""
    ## Getting Started
    1. Upload your data
    2. Configure parameters
    3. Run analysis
    """)

sidebar: DeltaGenerator
# Access sidebar through st.sidebar
# All regular widgets and containers work in sidebar context

import streamlit as st

# Sidebar content
st.sidebar.title("Navigation")
page = st.sidebar.selectbox("Choose page:", ["Home", "Data", "Results"])

st.sidebar.markdown("---")
st.sidebar.write("Settings")
debug_mode = st.sidebar.checkbox("Debug mode")
batch_size = st.sidebar.slider("Batch size", 1, 100, 32)

# Sidebar with sections
with st.sidebar:
    st.markdown("### Filters")
    
    category = st.selectbox("Category:", ["All", "A", "B", "C"])
    date_range = st.date_input("Date range:")
    
    st.markdown("### Options") 
    show_raw_data = st.checkbox("Show raw data")
    export_format = st.radio("Export format:", ["CSV", "JSON"])

# Main content area
st.title(f"Current page: {page}")
if debug_mode:
    st.write(f"Debug: Batch size is {batch_size}")

def form(key: str, clear_on_submit: bool = False) -> DeltaGenerator:
    """
    Create a form container to batch widget interactions.
    
    Parameters:
    - key: Unique key for the form
    - clear_on_submit: Whether to clear form inputs after submission
    
    Returns:
    DeltaGenerator: Form container
    """

def form_submit_button(label: str = "Submit", help: str = None, on_click=None, args=None, kwargs=None, type: str = "primary", disabled: bool = False, use_container_width: bool = False) -> bool:
    """
    Display a form submit button (must be used inside a form).
    
    Parameters:
    - label: Text displayed on the submit button
    - help: Tooltip text shown on hover
    - on_click: Callback function executed on submit
    - args: Arguments passed to callback function
    - kwargs: Keyword arguments passed to callback function
    - type: Button type ("primary" or "secondary")
    - disabled: Whether the button is disabled
    - use_container_width: Whether to use full container width
    
    Returns:
    bool: True if submit button was clicked, False otherwise
    """

import streamlit as st

# Simple form
with st.form("my_form"):
    st.write("User Information")
    name = st.text_input("Name")
    age = st.number_input("Age", min_value=0, max_value=120)
    email = st.text_input("Email")
    
    # Form submission
    submitted = st.form_submit_button("Submit")
    
    if submitted:
        st.success(f"Form submitted for {name}, age {age}, email {email}")

# Form with sections and validation
with st.form("contact_form", clear_on_submit=True):
    st.markdown("### Contact Information")
    
    col1, col2 = st.columns(2)
    with col1:
        first_name = st.text_input("First Name")
        phone = st.text_input("Phone")
    with col2:
        last_name = st.text_input("Last Name")
        email = st.text_input("Email")
    
    st.markdown("### Message")
    subject = st.selectbox("Subject", ["General Inquiry", "Support", "Feedback"])
    message = st.text_area("Message", height=100)
    
    # Submit with validation
    if st.form_submit_button("Send Message"):
        if first_name and last_name and email and message:
            st.success("Message sent successfully!")
            st.balloons()
        else:
            st.error("Please fill in all required fields")

# Form with custom submit handling
def handle_submission():
    st.session_state.form_submitted = True

with st.form("custom_form"):
    data = st.text_input("Enter data:")
    
    submitted = st.form_submit_button(
        "Process Data",
        on_click=handle_submission
    )
    
    if submitted and st.session_state.get("form_submitted", False):
        st.write(f"Processing: {data}")
        st.session_state.form_submitted = False

import streamlit as st

# Header section
header_container = st.container()
with header_container:
    st.title("Dashboard")
    col1, col2, col3 = st.columns(3)
    with col1:
        st.metric("Total Users", "1,234", "+5%")
    with col2:
        st.metric("Revenue", "$12.3K", "+12%")  
    with col3:
        st.metric("Growth", "8.2%", "+1.2%")

# Main content with sidebar navigation
with st.sidebar:
    st.selectbox("Time Period", ["Last 7 days", "Last 30 days", "Last 90 days"])
    st.multiselect("Filters", ["Region A", "Region B", "Region C"])

# Tabbed main content
tab1, tab2 = st.tabs(["Overview", "Details"])

with tab1:
    # Overview content with expandable sections
    with st.expander("Charts", expanded=True):
        col1, col2 = st.columns(2) 
        with col1:
            st.line_chart([1, 3, 2, 4, 5])
        with col2:
            st.bar_chart([2, 1, 3, 4, 2])
    
    with st.expander("Data Table"):
        st.dataframe({"A": [1, 2, 3], "B": [4, 5, 6]})

with tab2:
    # Details content
    st.write("Detailed view content here")

# Footer placeholder
footer = st.empty()
footer.markdown("---")
footer.caption("Last updated: 2024-01-01")