pip install streamlit
streamlit run app.py

import streamlit as st
import pandas as pd
import plotly.express as px

# Page config (must be first Streamlit command)
st.set_page_config(
    page_title="My Dashboard",
    page_icon="📊",
    layout="wide",
    initial_sidebar_state="expanded"
)

# Title
st.title("📊 Analytics Dashboard")
st.markdown("Real-time insights into your data")

# Sidebar
with st.sidebar:
    st.header("Filters")
    date_range = st.date_input("Date Range", [])
    category = st.selectbox("Category", ["All", "Sales", "Marketing", "Support"])

# Main content
col1, col2, col3 = st.columns(3)

with col1:
    st.metric("Total Revenue", "$45,231", "+12.5%")

with col2:
    st.metric("Active Users", "2,345", "+5.2%")

with col3:
    st.metric("Conversion Rate", "3.2%", "-0.4%", delta_color="inverse")

# Charts
st.subheader("Revenue Over Time")
chart_data = pd.DataFrame({
    'date': pd.date_range('2024-01-01', periods=30),
    'revenue': [100 + i * 10 + (i % 5) * 20 for i in range(30)]
})
st.line_chart(chart_data.set_index('date'))

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

# Custom widths
left, right = st.columns([2, 1])  # 2:1 ratio

# With gaps
col1, col2 = st.columns(2, gap="large")  # small, medium, large

with col1:
    st.write("Left content")

with col2:
    st.write("Right content")

# Container for grouping
with st.container():
    st.header("Section Header")
    st.write("Content inside container")

# Expandable section
with st.expander("Advanced Options", expanded=False):
    st.slider("Parameter 1", 0, 100, 50)
    st.slider("Parameter 2", 0, 100, 25)

# Tabs
tab1, tab2, tab3 = st.tabs(["Overview", "Details", "Settings"])

with tab1:
    st.write("Overview content")

with tab2:
    st.write("Details content")

with st.sidebar:
    st.header("Navigation")
    page = st.radio("Go to", ["Home", "Analytics", "Settings"])

    st.divider()

    st.header("Filters")
    start_date = st.date_input("Start Date")
    end_date = st.date_input("End Date")

    st.divider()

    if st.button("Apply Filters"):
        st.success("Filters applied!")

# Text inputs
name = st.text_input("Name", placeholder="Enter your name")
description = st.text_area("Description", height=100)

# Numbers
age = st.number_input("Age", min_value=0, max_value=120, value=25)
price = st.slider("Price Range", 0.0, 1000.0, (100.0, 500.0))

# Selections
option = st.selectbox("Choose one", ["A", "B", "C"])
options = st.multiselect("Choose many", ["A", "B", "C", "D"])
color = st.color_picker("Pick a color", "#00f900")

# Date/Time
date = st.date_input("Select date")
time = st.time_input("Select time")

# Files
uploaded_file = st.file_uploader("Upload CSV", type=["csv", "xlsx"])
if uploaded_file:
    df = pd.read_csv(uploaded_file)
    st.dataframe(df)

# Toggles
agree = st.checkbox("I agree to terms")
enabled = st.toggle("Enable feature")

import pandas as pd

# DataFrame
df = pd.DataFrame({
    'Name': ['Alice', 'Bob', 'Charlie'],
    'Sales': [100, 150, 200],
    'Growth': [0.1, 0.25, 0.15]
})

# Basic table
st.dataframe(df)

# Editable table
edited_df = st.data_editor(df, num_rows="dynamic")

# Styled DataFrame
st.dataframe(
    df.style.highlight_max(subset=['Sales']),
    use_container_width=True,
    hide_index=True
)

# Column configuration
st.dataframe(
    df,
    column_config={
        "Growth": st.column_config.ProgressColumn(
            "Growth",
            format="%.0f%%",
            min_value=0,
            max_value=1,
        ),
        "Sales": st.column_config.NumberColumn(
            "Sales",
            format="$%d"
        )
    }
)

# Metrics
col1, col2, col3 = st.columns(3)
col1.metric("Revenue", "$45,231", "+12.5%")
col2.metric("Users", "2,345", "+5.2%")
col3.metric("Bounce Rate", "32%", "-8%", delta_color="inverse")

# JSON
st.json({"name": "Alice", "data": [1, 2, 3]})

import pandas as pd
import numpy as np

# Sample data
chart_data = pd.DataFrame(
    np.random.randn(20, 3),
    columns=['A', 'B', 'C']
)

# Line chart
st.line_chart(chart_data)

# Area chart
st.area_chart(chart_data)

# Bar chart
st.bar_chart(chart_data)

# Scatter chart
st.scatter_chart(chart_data, x='A', y='B', size='C')

import plotly.express as px
import plotly.graph_objects as go

# Plotly Express
fig = px.line(df, x='date', y='value', color='category',
              title='Trend Over Time')
st.plotly_chart(fig, use_container_width=True)

# Plotly Graph Objects
fig = go.Figure()
fig.add_trace(go.Scatter(x=df['date'], y=df['value'],
                         mode='lines+markers', name='Value'))
fig.update_layout(
    title='Custom Chart',
    xaxis_title='Date',
    yaxis_title='Value',
    template='plotly_white'
)
st.plotly_chart(fig, use_container_width=True)

import altair as alt

chart = alt.Chart(df).mark_bar().encode(
    x='category:N',
    y='value:Q',
    color='category:N'
).properties(width='container', height=400)

st.altair_chart(chart, use_container_width=True)

import streamlit as st
import pandas as pd

# Cache data loading
@st.cache_data(ttl=3600)  # Cache for 1 hour
def load_data(url: str) -> pd.DataFrame:
    return pd.read_csv(url)

# Cache ML models
@st.cache_resource
def load_model():
    import joblib
    return joblib.load('model.pkl')

# Usage
df = load_data("https://example.com/data.csv")  # Cached
model = load_model()  # Cached singleton

import streamlit as st

# Initialize state
if 'counter' not in st.session_state:
    st.session_state.counter = 0

if 'messages' not in st.session_state:
    st.session_state.messages = []

# Update state
if st.button("Increment"):
    st.session_state.counter += 1

st.write(f"Counter: {st.session_state.counter}")

# Form with state
with st.form("my_form"):
    name = st.text_input("Name")
    submitted = st.form_submit_button("Submit")

    if submitted:
        st.session_state.messages.append(f"Hello, {name}!")

# Display messages
for msg in st.session_state.messages:
    st.write(msg)

import time

# Progress bar
progress = st.progress(0)
for i in range(100):
    time.sleep(0.01)
    progress.progress(i + 1)

# Spinner
with st.spinner("Loading..."):
    time.sleep(2)
st.success("Done!")

# Status messages
st.success("Operation completed!")
st.info("This is informational")
st.warning("This is a warning")
st.error("This is an error")
st.exception(Exception("An error occurred"))

# Toast notifications
st.toast("File saved!", icon="✅")

my_app/
├── streamlit_app.py      # Main entry (can be empty)
└── pages/
    ├── 1_📊_Dashboard.py
    ├── 2_📈_Analytics.py
    └── 3_⚙️_Settings.py

# pages/1_📊_Dashboard.py
import streamlit as st

st.title("Dashboard")
st.write("Dashboard content here")

# Create requirements.txt
pip freeze > requirements.txt

# Push to GitHub and connect to Streamlit Cloud

FROM python:3.11-slim

WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt

COPY . .

EXPOSE 8501

CMD ["streamlit", "run", "app.py", "--server.port=8501", "--server.address=0.0.0.0"]