lovuikeng•2mo ago

wasm export local file read

exporting notebook to wasm

$ uv tool run marimo@0.10.2 export html-wasm apps.py -o wasm --mode run

serve it on python http server, after loading the index file, caught

This cell raised an exception: FileNotFoundError('[Errno 44] No such file or directory: 'data.csv''

does wasm export support reading local file?

Solution:

It does not at the moment. We have an issue internally tracking this

Jump to solution

12 Replies

Hall•2mo ago

Someone will reply to you shortly. In the meantime, this might help:

Solution

Myles Scolnick•2mo ago

It does not at the moment. We have an issue internally tracking this

Myles Scolnick•2mo ago

Is difficult since we would need to bundle this And there is a limit of what wasm can support in terms of file size

lovuikengOP•2mo ago

ok, just to confirm, thank you, wasm standalone looks really great feature to explore 🙂

mcaggio•2mo ago

not sure if I understood the question correctly, but if you want to make a file available to the pyodide kernel, provided the file is available for download from a url, you can download it to the local wasm kernel filesystem

from pyodide.http import pyfetch

response = await pyfetch("https://raw.githubusercontent.com/caggionim/marimo_rheofit/refs/heads/main/models.py")
with open('models.py', 'wb') as file:
    file.write(await response.bytes())

from pyodide.http import pyfetch

response = await pyfetch("https://raw.githubusercontent.com/caggionim/marimo_rheofit/refs/heads/main/models.py")
with open('models.py', 'wb') as file:
    file.write(await response.bytes())

mcaggio•2mo ago

I have an example in this repository https://github.com/caggionim/marimo_rheofit

GitHub

GitHub - caggionim/marimo_rheofit: testing_marimo_app

testing_marimo_app. Contribute to caggionim/marimo_rheofit development by creating an account on GitHub.

lovuikengOP•2mo ago

thanks, true that reading CSV from URL does work, the intention here is to read from local file path

flipside•7d ago

Hi, I was wondering, how do you make a cell async? I want to use pyfetch both during dev and deployment but it complains "'await' outside async function" and I think this is because in your code, cell using pyfetch starts with async def, but not sure how I can configure that? https://github.com/caggionim/marimo_rheofit/blob/6b3b830c463ee724bf99710f1a56ef35676cfb52/rheology_flowcurvefit.py#L15

GitHub

marimo_rheofit/rheology_flowcurvefit.py at 6b3b830c463ee724bf99710f...

testing_marimo_app. Contribute to caggionim/marimo_rheofit development by creating an account on GitHub.

RJ Budzyński•7d ago

Depending on where you want to download from, you may be struggling with CORS though.

mcaggio•7d ago

my understanding is that the pyfetch from pyodide.html returns a promise, not the actual response, so you need to await the response. When you use await in a marimo cell my understanding is that marimo automatically makes that cell async. In the example the second cell where await is used is defined as async

@app.cell
def __():
    import sys
    import marimo as mo
    return mo, sys


@app.cell
async def __():
    from pyodide.http import pyfetch

    response = await pyfetch("https://raw.githubusercontent.com/caggionim/marimo_rheofit/refs/heads/main/models.py")
    with open('models.py', 'wb') as file:
        file.write(await response.bytes())

    response = await pyfetch("https://raw.githubusercontent.com/caggionim/marimo_rheofit/refs/heads/main/rheo_widgets.py")
    with open('rheo_widgets.py', 'wb') as file:
        file.write(await response.bytes())

@app.cell
def __():
    import sys
    import marimo as mo
    return mo, sys


@app.cell
async def __():
    from pyodide.http import pyfetch

    response = await pyfetch("https://raw.githubusercontent.com/caggionim/marimo_rheofit/refs/heads/main/models.py")
    with open('models.py', 'wb') as file:
        file.write(await response.bytes())

    response = await pyfetch("https://raw.githubusercontent.com/caggionim/marimo_rheofit/refs/heads/main/rheo_widgets.py")
    with open('rheo_widgets.py', 'wb') as file:
        file.write(await response.bytes())

You are right but at least looks like it works when you host an app on Github pages you can download files from the same repository without problems.

RJ Budzyński•7d ago

Yes, githubusercontent.com url work ok

lovuikengOP•6d ago

reminder: marimo now makes serving file/data on WASM so much easier https://docs.marimo.io/guides/wasm/#including-data

WebAssembly notebooks - marimo

The next generation of Python notebooks

wasm export local file read

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