How can I load a local library in Brython?

Question

plot.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link href="https://fonts.googleapis.com/css2?family=Open+Sans&display=swap" rel="stylesheet">
    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.14.0/css/all.css" integrity="sha384-HzLeBuhoNPvSl5KYnjx0BT+WB0QEEqLprO+NBkkk5gbc67FTaL7XIGa2w1L0Xbgc" crossorigin="anonymous">
    <link rel="stylesheet" type="text/css" href="../static/css/css5.css">
    <title>Protein Structure Analyzer</title>
    <script type="text/javascript" src="../static/jquery/jquery-3.6.3.js"></script>
    <script src="../static/brython/Brython-3.11.1/brython.js"></script>
    <script src="../static/brython/Brython-3.11.1/brython_stdlib.js"></script>
</head>
<body onload="brython()">
<div class="angry-grid">
    <div class="header-div">SURPASS Plots</div>
    <div class="plot-div"></div>
    <div class="form-div">
        <form></form>
    </div>
    <div class="footer-div">
        Footer
    </div>
</div>
<script type="text/python">
from PersistanceUtils import *

energy_list, time_list = PersistanceUtils.get_plot_data2("{{unique_key}}")

</script>
</body>
</html>

Debug

brython.js:9479          GET http://127.0.0.1:5000/PersistanceUtils.py?v=1676882840703 404 (NOT FOUND)
brython.js:9484 Error 404 means that Python module PersistanceUtils was not found at url http://127.0.0.1:5000/PersistanceUtils.py
brython.js:9479          GET http://127.0.0.1:5000/PersistanceUtils/__init__.py?v=1676882840718 404 (NOT FOUND)
brython.js:9484 Error 404 means that Python module PersistanceUtils was not found at url http://127.0.0.1:5000/PersistanceUtils/__init__.py
brython.js:9479          GET http://127.0.0.1:5000/static/brython/Brython-3.11.1/Lib/site-packages/PersistanceUtils.py?v=1676882840737 404 (NOT FOUND)
brython.js:9484 Error 404 means that Python module PersistanceUtils was not found at url http://127.0.0.1:5000/static/brython/Brython-3.11.1/Lib/site-packages/PersistanceUtils.py
brython.js:9479          GET http://127.0.0.1:5000/static/brython/Brython-3.11.1/Lib/site-packages/PersistanceUtils/__init__.py?v=1676882840753 404 (NOT FOUND)
brython.js:9484 Error 404 means that Python module PersistanceUtils was not found at url http://127.0.0.1:5000/static/brython/Brython-3.11.1/Lib/site-packages/PersistanceUtils/__init__.py
brython.js:14320 Traceback (most recent call last):
  File "http://127.0.0.1:5000/plot#__main__", line 1, in <module>
    from PersistanceUtils import *
ModuleNotFoundError: PersistanceUtils

There is a file named PersistanceUtils.py in the application root. The Brython script is unable to load it.

How can I load it?

Does this mean that the file should be found at one of the URLs listed in the debug output? Have you tried to paste this URL in the browser to load it manually? What happened? — Michael Butscher, Feb 20 '23 at 09:35
@MichaelButscher, The specified python file is one level above the `index.html` or `plot.html`. — user366312, Feb 20 '23 at 09:40
This means `http://127.0.0.1:5000/PersistanceUtils.py` should be right? Have you tried it in browser? — Michael Butscher, Feb 20 '23 at 09:45
@MichaelButscher, Check the directory structure. `http://127.0.0.1:5000/` == `templates` — user366312, Feb 20 '23 at 09:48
If you mean that `http://127.0.0.1:5000/PersistanceUtils.py` maps to file location `FrontEnd/templates/PersistanceUtils.py` what would be the right URL to retrieve the file? — Michael Butscher, Feb 20 '23 at 09:56
@MichaelButscher, That is the question I don't know the answer to. — user366312, Feb 20 '23 at 09:57
Then this is actually a question about flask and how to map the URL to the right file location on server side. — Michael Butscher, Feb 20 '23 at 10:02

score 0 · Answer 1 · answered Feb 20 '23 at 12:43

You can place your python files for Brython inside the static folder. Then you import them with a script tag, whereby an id attribute has to be specified.

<script type="text/python" id="demo" src="{{ url_for('static', filename='demo.py') }}"></script>

In the import commando you now refer to the defined id of the module.

<script type="text/python">
    from demo import *
    
    # Use your import here.
</script>

How can I load a local library in Brython?

1 Answers1