Streamlit enables rapid development of web applications using Python, requiring no frontend expertise. It transforms Python scripts into shareable web pages in minutes, supporting free deployment.

Install Streamlit using pip:

pip install streamlit

Verify installation by running:

streamlit hello

Navigate to the provided local URL in you're browser to confirm.

To run an application, create a Python file and execute:

streamlit run app.py

This launches a local server, typically at http://localhost:8501.

Import Streamlit in your script:

import streamlit as st

Display text with st.write():

st.write('Hello World!')

Create haedings using st.title():

st.title('Application Title')

Markdown is supported directly:

"# Main Heading"
"## Subheading"
"""
```python
print('Code block')

"""

Render images with `st.image()`:
```python
st.image('image.jpg', width=500)

Display data tables. Static tables use st.table():

import pandas as pd
data = {'Name': ['Alice', 'Bob'], 'Score': [85, 92]}
st.table(data)

Interactive tables use st.dataframe():

df = pd.DataFrame(data)
st.dataframe(df)

Add separators with st.divider():

st.divider()

Use Python variables and control sturctures:

x = 15
y = 25
st.write(x * y)

if x > 10:
    st.write('x is greater than 10')

for i in range(5):
    st.write(i)

Create input fields. Text input:

username = st.text_input('Enter your name:')
if username:
    st.write(f'Welcome, {username}')

Pasword input:

password = st.text_input('Password:', type='password')

Numeric input:

age = st.number_input('Age:', value=25, min_value=0, max_value=120, step=1)

Multi-line text area:

feedback = st.text_area('Comments:')

Interactive elements. Checkbox:

agreed = st.checkbox('I agree to the terms')
if agreed:
    st.write('Terms accepted')

Radio buttons:

choice = st.radio('Select option:', ['Option A', 'Option B'], index=0)

Single-select dropdown:

item = st.selectbox('Choose an item:', ['Item 1', 'Item 2', 'Item 3'])

Multi-select dropdown:

selected = st.multiselect('Select items:', ['A', 'B', 'C'])
for s in selected:
    st.write(s)

Slider:

value = st.slider('Adjust value:', min_value=0, max_value=100, value=50, step=5)

Button:

clicked = st.button('Submit')
if clicked:
    st.write('Button pressed')

File uploader:

file = st.file_uploader('Upload a file:', type=['csv', 'txt'])
if file:
    st.write(f'Uploaded: {file.name}')

Layout components. Sidebar:

with st.sidebar:
    query = st.text_input('Search:')

Columns:

col1, col2 = st.columns(2)
with col1:
    st.write('Column 1')
with col2:
    st.write('Column 2')

Tabs:

tab_a, tab_b = st.tabs(['Tab A', 'Tab B'])
with tab_a:
    st.write('Content A')
with tab_b:
    st.write('Content B')

Expander:

with st.expander('Details'):
    st.write('Hidden content')

Charts, such as line charts:

import numpy as np
chart_data = np.random.randn(20, 3)
st.line_chart(chart_data)

Multi-page applications are created by adding a pages directory in the project root. Place additional Python files in this folder to automatically genearte navigation.

Deploy applications via Streamlit Community Cloud. Push your code to a GitHub repository, then visit share.streamlit.io to connect the repository and deploy. Configure the main file path and optional custom subdomain.