How to add a hyperlink for downloading a dataframe as csv using Pandas

Question

I’m working with a .csv cars dataset (that I got from here) and I’m trying to:

Convert this .csv to a pandas dataframe (Done, see df)
Group the dataframe by cars models (Done, see grouped_df)
Make a column with a hyperlink to download the .csv/df for each car in the grouped_df (To be finalized)

CODE :

import pandas as pd
from IPython.display import HTML

df = pd.read_csv("cars.csv", delimiter=';', skiprows=[1])

display(df.head(5))

grouped_df = df.groupby('Car').agg(NumberOfCars=('Car', 'size'), 
                                   MeanOfWeight=('Weight', 'mean'),
                                   MeanOfAcceleration=('Acceleration', 'mean'))

grouped_df.insert(len(grouped_df.columns), "DownloadCsv", 'Download the details (.csv)')

grouped_df['DownloadCsv'] = grouped_df['DownloadCsv'].apply(lambda x: f'<a href="https://stackoverflow.com/{x}">{x}</a>')

HTML(grouped_df.sample(5).to_html(escape=False))

>>> `display(df.head(5))`

>>> `HTML(grouped_df.sample(5).to_html(escape=False))`

For example, if the user click on "Download the details (.csv)" of the second row, he should get a .csv of all rows in df where the column car equals to "Ford Torino 500".

By the way, the code will be implemented in a streamlit app.

Is there any way to achieve this ? Do you have any propositions, please ?

EDIT :

By following @furas’s suggestion, I made this code :

b_buf = io.BytesIO()
with gzip.open(b_buf, 'wb') as f:
    f.write(df.to_csv().encode())
b_buf.seek(0)
with open("my_zip.zip", "wb") as f:
    f.write(b_buf.getvalue())

csv_url = base64.b64encode(b_buf.getvalue()).decode()

grouped_df['DownloadCsv'] = grouped_df['DownloadCsv'].apply(
    lambda x: '<a.href="data:text/csv;base64,"' + csv_url)

st.write(HTML(grouped_df.sample(5).to_html(escape=False)), unsafe_allow_html=True)

Unfortunately, the column grouped_df['DownloadCsv'] seems to be empty in the streamlit app !
What am I missing ?

Asked By: L'Artiste

||

Source

Answer 1

Since you aim to integrate this in streamlit, why not use a streamlit button to download the csv?
The example below writes the dataframe to streamlit columns and adds download buttons for the individual csv files.

import streamlit as st
import pandas as pd

df = pd.read_csv("cars.csv", delimiter=';', skiprows=[1])

grouped_df = df.groupby('Car').agg(NumberOfCars=('Car', 'size'), 
                                   MeanOfWeight=('Weight', 'mean'),
                                   MeanOfAcceleration=('Acceleration', 'mean')).reset_index()

grouped_df.insert(len(grouped_df.columns), "DownloadCsv", 'Download the details (.csv)')

colms = st.columns((2, 1, 1, 1, 2))

#write headers
for col, field_name in zip(colms, grouped_df.columns):
    col.write(f'**{field_name}**')

def writerow(row):
    col1, col2, col3, col4, col5 = st.columns((2, 1, 1, 1, 2))
    with col1:
        st.write(row['Car'])
    with col2:
        st.write(row['NumberOfCars'])
    with col3:
        st.write(row['MeanOfWeight'])
    with col4:
        st.write(row['MeanOfAcceleration'])
    with col5:
        st.download_button("Download details (.csv)", df[df['Car'] == row['Car']].to_csv(), f"details_{row['Car']}.csv", "text/csv")
        
grouped_df.apply(writerow, axis=1)

Result:

Answered By: RJ Adriaansen

How to add a hyperlink for downloading a dataframe as csv using Pandas

Question:

CODE :

>>> `display(df.head(5))`

>>> `HTML(grouped_df.sample(5).to_html(escape=False))`

EDIT :

Answers:

How to add a hyperlink for downloading a dataframe as csv using Pandas

Question:

CODE :

>>> display(df.head(5))

>>> HTML(grouped_df.sample(5).to_html(escape=False))

EDIT :

Answers:

>>> `display(df.head(5))`

>>> `HTML(grouped_df.sample(5).to_html(escape=False))`