Dash Caching problem (duckdb IOException, conflicting lock, PandasAI)


I was playing around with PandasAI and am facing a caching problem:

When I’m using the following code (what is just a code copy from here and here:

from dash import Dash, html, dcc, callback, Output, Input
import plotly.express as px
import pandas as pd

from pandasai.llm import OpenAI
llm = OpenAI(api_token="put-in-your-api-token-here")

import seaborn as sns
from pandasai import SmartDataframe

df = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/gapminder_unfiltered.csv')

app = Dash(__name__)

app.layout = html.Div([
    html.H1(children='Title of Dash App', style={'textAlign':'center'}),
    dcc.Dropdown(df.country.unique(), 'Canada', id='dropdown-selection'),

data = sns.load_dataset('titanic')
df = SmartDataframe(data, config={'llm': llm})

response = df.chat("""Return the survived class in percentage""")


    Output('graph-content', 'figure'),
    Input('dropdown-selection', 'value')
def update_graph(value):
    dff = df[df.country==value]
    return px.line(dff, x='year', y='pop')

if __name__ == '__main__':

The Dash app is crashing because of a caching error:

duckdb.duckdb.IOException: IO Error: Could not set lock on file "/Users/.../dash_app/cache/cache_db_0.9.db": Conflicting lock is held in /Library/Frameworks/Python.framework/Versions/3.12/Resources/Python.app/Contents/MacOS/Python (PID 31194) by user .... See also https://duckdb.org/docs/connect/concurrency

Well, I tried already to downgrade Dash, PandasAI or even DuckDB, but found no solution.

Maybe you have a better idea to solve that?

Thank you again and have a nice weekend :slight_smile:

Hello @DaGloom,

I’d make sure that you are only running the function once, and maybe try not reusing the same variable?

Typically, I think dash has a preflight to make sure that all layouts and things run, especially with debug=True, this might be what is causing your issue.