Streamlit.io

a First Look

Was ist das Schwierigste Problem in der IT?

Latest Version: 0.71

$ pipenv install streamlit
$ pipenv shell
$ streamlit hello

Welcome to Streamlit. Check out our demo in your browser.

  Local URL: http://localhost:8502
  Network URL: http://5.179.250.48:8502

Hello World

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

st.title('My first app')
st.write("Using data to create a table:")
st.write(pd.DataFrame({
    'first column': [1, 2, 3, 4],
    'second column': [10, 20, 30, 40]
}))
df = pd.DataFrame({
    'first column': [1, 2, 3, 4],
    'second column': [10, 20, 30, 40]
})

df

chart_data = pd.DataFrame(
    np.random.randn(20, 3),
    columns=['a', 'b', 'c'])

st.line_chart(chart_data)

test_app.py

$ streamlit run test_app.py

​# showing geographical map
st.map()

# Markdown text if checkbox activated
if st.checkbox("Click me"):
    st.markdown("# Header")

# a unique select box in the sidebar
option = st.sidebar.selectbox("Select number", [1,2,3], key="unique")
"You selected", option

# using columns and buttons
left_column, right_column = st.beta_columns(2)
pressed = left_column.button('Press me?')
if pressed:
    right_column.write("Woohoo!")​

# changing order of appearance
slot_1 = st.empty()
st.text("This will appear last")
slot_1.text("This will appear first")

Mini Tutorial

​df = pd.DataFrame()
# IDE says: "Statement seems to have no effect"
# but generates a table view of the dataframe
df

# it is not possible to center the content, yet
st.write(df.describe())

# By default info() does only return None
# So we need some workaround to see the output  
buf = io.StringIO()
df.info(buf=buf, verbose=True)
st.text(buf.getvalue())

# we can use matplotlib and even seaborn plots
# set_theme will globally change the layout of matplotlib plots
import seaborne as sns
sns.set_theme()
st.pyplot(sns.relplot(data=dax, kind="line"))

# Select the property ".figure" from the pandas inbuilt plotting
st.pyplot(df.plot().figure)

# hist returns a numpy array of subplots
# we need to select the first one
hist = df.hist(bins=100)
st.pyplot(hist[0, 0].figure)

TIPS & Quirks

1. ​Within your company​
   • "​​Streamlit for teams" not yet available
2. ​In the Cloud (needs github repo)
   • ​​request an invite
   • select a repo, branch and file
   • click deploy
   • any time you push will update your app immediatelly
   • Continuous Deployment! Very Nice!
3. Examples
   1. https://share.streamlit.io/asmaier/streamlit-demo/main/stocky.py
   2. https://share.streamlit.io/asmaier/streamlit-demo/main/errorbars.py

Deployment

STREAMLIT VS. DASH

see also medium.com: Plotly Dash vs Streamlit

Big Picture

jupyter notebooks < streamlit < plotly dash

Competitors

• Voila - Converts Jupyter notebooks to webapps
• Panel - webapps build on top of bokeh
• Shiny - R powered webapps (especially https://www.shinyapps.io/)

OPINION

medium.com: A roundup of Data Visualization Frameworks

panel.holoviz.org - Comparisons

Maybe we will finally see

something similar to

 https://demonstrations.wolfram.com ,

but this time open source

and based on

Streamlit and Python

???

FUTURE

THE END