Streamlit Sample codes

Codes

• Example- Usage of Slider, SelectBox & Miltiselect

    import streamlit as st
    import numpy as np
  
    x = st.slider('Select a value')
    st.write(x, 'squared value is', x * x)
  
    Exp = streamlit.selectbox("Choose your Experience: ", np.arange(1, 40, 1))
  
    lan = st.multiselect("Which is your favorite language?", 
                     ["Python", "JavaScript",
                     "Java", "C", "Julia"])
  

• Example- Usage of dataframe

    import pandas as pd
    import streamlit as st
  
    @st.cache
    def load_data():
        df = pd.read_csv("data.csv") # csv
        #df = pd.read_excel("data.excel") #excel
        return df
  
    # Will only run once if already cached
    df = load_data()
  

• Example- Jupyter Notebook

    # Run jupyter notebook in streamlit using 3 steps below
    - jupyter nbconvert --to script scriptname.ipynb
    - awk '!/ipython/' scriptname.py > [temp.py](http://temp.py/) && mv [temp.py](http://temp.py/) [app.py](http://app.py/) && rm scriptname.py
    - streamlit run [app.py](http://app.py/)
    Refer the blog more details https://learnups2020.wordpress.com/2020/11/07/streamlit-code-running-from-jupyter-notebook/
  

• Example- Altair Chart

    # Alt Chart example
    import pandas as pd
    import numpy as np
    import altair as alt
    import streamlit as st
  
    df = pd.DataFrame(np.random.randn(100, 3), columns=['a', 'b', 'c'])
    c = alt.Chart(df).mark_circle().encode(x='a', y='b', size='c',  
                                    color='c')
    st.altair_chart(c, width=-1)
  

• Example- Simple Calculator App using sqlite DB

    # Simple Calculator
    import pandas as pd
    from pathlib import Path
    import sqlite3
    from sqlite3 import Connection
    import streamlit as st
  
    URI_SQLITE_DB = "test.db"
  
  
    def main():
    st.title("Simple Calculator")
    st.markdown("Select two inputs from sidebar.")
    
    conn = get_connection(URI_SQLITE_DB)
    init_db(conn)
  
    build_sidebar(conn)
    display_data(conn)
    run_calculator(conn)
  
  
    def init_db(conn: Connection):
            conn.execute(
                    """CREATE TABLE IF NOT EXISTS test
                    (
                            INPUT1 INT,
                            INPUT2 INT
                    );"""
            )
            conn.commit()
  
  
    def build_sidebar(conn: Connection):
            st.sidebar.header("Inputs")
            input1 = st.sidebar.slider("value-1", 0, 100)
            input2 = st.sidebar.slider("value-2", 0, 100)
            if st.sidebar.button("Save to database"):
                    conn.execute(f"INSERT INTO test (INPUT1, INPUT2) VALUES ({input1}, {input2})")
                    conn.commit()
  
  
    def display_data(conn: Connection):
            if st.checkbox("Display data from the database"):
                    st.dataframe(get_data(conn))
  
  
    def run_calculator(conn: Connection):
            if st.button("Calculate Sum"):
                    st.info("Sum of two inputs function is called.")
                    df = get_data(conn)
                    st.write(df.sum())
  
  
    def get_data(conn: Connection):
            df = pd.read_sql("SELECT * FROM test", con=conn)
            return df
  
  
    @st.cache(hash_funcs={Connection: id})
    def get_connection(path: str):
            """Put the connection in cache to reuse if path does not change between Streamlit reruns.
            NB : https://stackoverflow.com/questions/48218065/programmingerror-sqlite-objects-created-in-a-thread-can-only-be-used-in-that-sa
            """
            return sqlite3.connect(path, check_same_thread=False)
  
  
    if __name__ == "__main__":
            main()
  

• Example- ProgressBar in sidebar and generate chart

    import streamlit as st 
    import time 
    import numpy as np
  
    progress_bar = st.sidebar.progress(0)
    status_text = st.sidebar.empty()
    last_rows = np.random.randn(1, 1)
    chart = st.line_chart(last_rows)
  
  
    for i in range(1, 101):
    new_rows = last_rows[-1, :] + np.random.randn(5, 1).cumsum(axis=0)
    status_text.text("%i%% Complete" % i)
    chart.add_rows(new_rows)
    progress_bar.progress(i)
    last_rows = new_rows
    time.sleep(0.05)
  
    progress_bar.empty()
  
    st.button("Re-run")
  

• Example- Streamlit Components Example

    import streamlit as st
  
    st.sidebar.subheader("Component 1")
  
    t1 = st.sidebar.text_input("Component 1 name")
    s1 = st.sidebar.slider("Component 1 value")
  
    st.sidebar.markdown("---")
  
    st.sidebar.subheader("Component 2")
    t2 = st.sidebar.text_input("Component 2 name")
    s2 = st.sidebar.slider("Component 2")
  
    st.title("Hello!")
  
    st.write(t1, s1)
    st.write(t2, s2)
  
  
    template = """
    <div class="markdown-text-container stText" style="width: 698px;">
    <div style="font-size: small;">This is paragraph 1 text.</div>
    <p>This is paragraph 2 text.</p>
    <p>This is paragraph 3 text.</p>
    </div>
    """
  

• Example- Streamlit Code Share Example

    Prerequisites
    - pip install streamlit-embedcode
    import streamlit as st
    from streamlit_embedcode import github_gist, gitlab_snippet, pastebin_snippet, codepen_snippet, ideone_snippet, tagmycode_snippet
  
    st.title("Github Gist Snippet")
    github_gist("https://gist.github.com/SurendraRedd/feaa6f29961501fa9fce7a45abc14651")
  
    st.title("Gitlab Snippet")
    gitlab_snippet("https://gitlab.com/snippets/2037642", height=400)
  
    st.title("Pastebin Snippet")
    pastebin_snippet("https://pastebin.com/Ryr8q1kq", width = 600, scrolling = False)
  
    st.title("Code Pen Snippet")
    codepen_snippet("https://codepen.io/surendra1985/pen/wvGREBb", width = 600, scrolling = False)
  
    st.title("Ideone Snippet")
    ideone_snippet("https://ideone.com/tXCake")
  
    st.title("Tagmycode Snippet")
    tagmycode_snippet("https://tagmycode.com/snippet/14517/streamlit-basic-concepts#.X6fD8WgzZPY")