I don't know why this is happening. I'm getting to grips with the Grok framework. While following the tutorial I encountered this error. When using TAL:attributes to link to a CSS style sheet, the index page loads with a system error message. The index file is called index.cpt If I change it to index.pt it loads correctly. Can anyone tell me why this is happening? Is the cpt file type restrictive or is it my code?
index.cpt:
<html>
<head>
<link rel="stylesheet" type="text/css"
tal:attributes="href static/style.css" />
</head>
<body>
<p>Hello world!</p>
</body>
</html>
style.css:
body {
background-color: #FF0000;
}
app.py:
import grok
from sample import resource
class Sample(grok.Application, grok.Container):
pass
class Index(grok.View):
pass
class Bye(grok.View):
pass
It appears that the newest version of Grok uses the 'Chameleon' language(.cpt files) but the tutorial is still based on the Zope language(.pt files). There are some nuances between them so that is why I was getting the system error.
It's just a language syntax problem. I'm just renaming the files as .pt files instead of .cpt and working with Zope.
Related
How can I import from a local module from pyscript? This is my code:
<html>
<head>
<link rel="stylesheet" href="https://pyscript.net/alpha/pyscript.css" />
<script defer src="https://pyscript.net/alpha/pyscript.js"></script>
<title>Title</title>
<py-env>
- paths:
- ../app/db_operations/BookOperations.py
</py-env>
</head>
<body>
<py-script>
from BookOperations import get_books_count
</py-script>
</body>
</html>
I'm trying to import the BookOperations file and the function get_books_count from it but I keep getting this error in the browser:
PyScript: Loading from file ../app/db_operations/BookOperations.py failed with error 404 (File not Found). Are your filename and path are correct?
This is the image of my local project structure
This is what I've tried so far:
write the path without the first dash /
(..app/db_operations/BookOperations.py)
using a single . at the
beginning of the path (./app/db_operations/BookOperations.py)
using no dots
writing the path like "app.db_operations.BookOperations.py"
(with . instead of /)
moving the py-env tag inside body tag
A couple of things:
Are you using a server program to serve your project? Something like VS Code's live server, or even Python's included http server will work. If your files aren't made accessible on the network, PyScript running in the browser won't be able to fetch them.
PyScript has moved on quite a bit from the Alpha version - the latest release is 2022.12.1 from mid-December. You'll find some increased functionality there; py-env: paths has been replaced with the much more flexible fetch configurations syntax (more info). Additionally, there are improved error messages for when fetching files fails that may be helpful.
I have developed a web-based tool, and currently trying to make it python-launchable. I figured using CEFpython is probably the way to do it. I followed the tutorial here and wrote the following code:
from cefpython3 import cefpython as cef
import base64
import platform
import sys
import threading
import os
HTML_code = """
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
<link href="static/css/main.css" rel="stylesheet" />
</head>
<body>
<div id="UI">
</div>
<div id="container"></div>
<script src="static/main.js"></script>
<script type="text/javascript">
function defineData(datainput){
console.log("start")
data = datainput;
var loc = window.location.pathname;
var dir = loc.substring(0, loc.lastIndexOf('/'));
console.log(loc);
console.log(dir);
Main();
}
</script>
</body>
</html>
"""
def html_to_data_uri(html):
html = html.encode("utf-8", "replace")
b64 = base64.b64encode(html).decode("utf-8", "replace")
ret = "data:text/html;base64,{data}".format(data=b64)
return ret
def main(config):
sys.excepthook = cef.ExceptHook # To shutdown all CEF processes on error
settings = {}
cef.Initialize(settings=settings)
browser = cef.CreateBrowserSync(url=html_to_data_uri(HTML_code),window_title="Test")
browser.SetClientHandler(LoadHandler(config))
cef.MessageLoop()
cef.Shutdown()
return
class LoadHandler(object):
def __init__(self, config):
self.config = config
def OnLoadingStateChange(self, browser, is_loading, **_):
"""Called when the loading state has changed."""
if not is_loading:
# Loading is complete. DOM is ready.
browser.ExecuteFunction("defineData", self.config)
unfortunately, unlike in the tutorial, my tool has to load a local .js file where the main function is defined (), and it seems if I code the html file this way, my working directory is not actually the directory where I call the script, but some strange place
the output of these lines are:
var loc = window.location.pathname;
var dir = loc.substring(0, loc.lastIndexOf('/'));
console.log(loc);
console.log(dir);
output:
text/html;base64,CjwhRE9DVFlQRSBodG1sPgo8aHRtbCBsYW5nPSJlbiI+Cgk8aGVhZD4KCQk8bWV0YSBjaGFyc2V0PSJ1dGYtOCI+CgkJPG1ldGEgbmFtZT0idmlld3BvcnQiIGNvbnRlbnQ9IndpZHRoPWRldmljZS13aWR0aCwgdXNlci1zY2FsYWJsZT1ubywgbWluaW11bS1zY2FsZT0xLjAsIG1heGltdW0tc2NhbGU9MS4wIj4KCQk8bGluayBocmVmPSJzdGF0aWMvY3NzL21haW4uY3NzIiByZWw9InN0eWxlc2hlZXQiIC8+CgkJPHN0eWxlIHR5cGU9InRleHQvY3NzIj4KCQkJKiB7CgkJCQkuYm9yZGV....
text
Could you help me finding the correct way of hard coding html code in python with the correct path? maybe I need to somehow set the path?
PS: I did try including the html code in a separate .html file, and it worked on Windows machines, but it seems MacOS doesn't like it. Since this tutorial did work on MAC, I'm trying to hard code the html part into the python script and hope it would work on both Windows and Mac
Well, the HTML document has been converted to the body of a data URI by html_to_data_uri, so the U[niversal]R[esource]L[ocator] (window.location) of the document isn't a location on a server, but the data URI itself (the "strange place" you mention).
Remember that URLs are a subset of URIs, and you passed the URI as a URL to CEF with:
browser = cef.CreateBrowserSync(url=html_to_data_uri(HTML_code),window_title="Test")
So, as long as you are using a data URI/URL, I don't think that window.location will be helpful. Instead, you could extract the HTML code into a separate .html file, and change that line to:
browser = cef.CreateBrowserSync(url="/path/to/that_html_file.html", window_title="Test")
I can get rebase() and include() to work with templates files on disk using rebase("base_template.tpl"), but am not seeing how to get this to run with templates stored in memory.
Here is my current effort:
from bottle import template
base_template = '''\
<html>
<head>
<title>{{title or 'No title'}}</title>
</head>
<body>
{{!base}}
</body>
</html>
'''
inner_template = '''\
% rebase(base_template, title='Page Title')
<p>Page Content ...</p>
'''
print(template(inner_template, base_template=base_template))
The above code results in a TemplateError.
Looks like it's a known issue with bottle, and this discussion https://github.com/bottlepy/bottle/issues/521 mentions a workaround.
However, no clues if it's working or not with latest version.
I wish to import my own library in Brython. This page of the documentation purports to show how, by adding the appropriate directory to the python path, but I can't make it work because I can't make Brython import sys.
Here's the simplest example code from the first page of the Brython documentation:
<html>
<head>
<script src="../src/Brython3.2.8/brython.js"></script>
</head>
<body onload="brython()">
<script type="text/python">
from browser import document, alert
def echo(ev):
alert(document["zone"].value)
document['mybutton'].bind('click', echo)
</script>
<input id="zone"><button id="mybutton">click !</button>
</body>
</html>
And that works fine.
But if I try to import sys:
<html>
<head>
<script src="../src/Brython3.2.8/brython.js"></script>
</head>
<body onload="brython()">
<script type="text/python">
import sys
from browser import document, alert
def echo(ev):
alert(document["zone"].value)
document['mybutton'].bind('click', echo)
</script>
<input id="zone"><button id="mybutton">click !</button>
</body>
</html>
Then the html will display but the button will not do anything.
The Console on Chrome shows the following error:
brython.js:6929 XMLHttpRequest cannot load file:///C:/Users/XXXXXXXXX/XXXXXX/src/Brython3.2.8/Lib/sys.py?v=1476283159509. Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, https, chrome-extension-resource.
$download_module # brython.js.6929
import_py # brython.js.6929
exec_module # brython.js.6929
etc etc
So, how can I import sys in brython, and/or how can I import my own library in python?
Thanks.
You need to include brython_stdlib.js in your html code. So your html should look like this:
<html>
<head>
<script src="../src/Brython3.2.8/brython.js"></script>
<script src="../src/Brython3.2.8/brython_stdlib.js"></script>
</head>
<body onload="brython()">
<script type="text/python">
import sys
from browser import document, alert
def echo(ev):
alert(document["zone"].value)
document['mybutton'].bind('click', echo)
</script>
<input id="zone"><button id="mybutton">click !</button>
</body>
</html>
Source Code : https://github.com/imvickykumar999/Brython/blob/master/index.html#L36
Deployed Code : https://imvickykumar999.github.io/Brython/
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Brython</title>
<script
type="text/javascript"
src="https://cdn.jsdelivr.net/npm/brython#3.8.9/brython.min.js">
</script>
<script
type="text/javascript"
src="https://cdn.jsdelivr.net/npm/brython#3.8.9/brython_stdlib.js">
</script>
<link
rel="stylesheet"
href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css"
integrity="sha384-9aIt2nRpC12Uk9gS9baDl411NQApFmC26EwAOH8WgZl5MYYxFfc+NcPb1dKGj7Sk"
crossorigin="anonymous">
</head>
<body onload="brython()">
<style>
body {
/* background-color: yellow; */
background-image: url(https://images.unsplash.com/photo-1573196872258-41425124bf5d?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1050&q=80);
/* background-repeat: no-repeat; */
}
</style>
<script type="text/python">
from browser import document
def calc(a, b, o):
d = { '+' : a+b,
'-' : a-b,
'*' : a*b,
'/' : a/b,
'%' : a%b
}
return f"({a}{o}{b})=({d[o]})"
a = float(input('Enter first number : '))
b = float(input('Enter second number : '))
o = input('Enter the Operator (+,-,*,/,%) : ')
document <= calc(a, b, o)
</script>
</body>
</html>
Brython cannot import from any Python package that is part of any Python installation on the user's computer. It works by transpiling to JavaScript and running in the browser's Javascript engine. It has no knowledge of any local Python installations, and does not require any such installations to exist.
To use Python's standard library
Add a script tag to include brython_stdlib.js as well as the base brython.js. Several CDNs provide this already.
The Brython implementation of the Python standard library does not match the reference implementation exactly. See the documentation for details on what is included and how it is organized.
Importing your own code from within the document
For organizational purposes, Python code within the HTML document can be split across multiple <script> tags. The id attribute for the tag gives a "module name" that can be used in import statements in other scripts, as long as that script has already executed. The documentation includes an example:
<script type="text/python" id="module">
def hello():
return "world"
</script>
<script type="text/python">
from browser import document
import module
document.body <= module.hello()
</script>
The browser will have loaded the first <script> tag first, creating a (JavaScript representation of) a Python module named module that contains the hello function. The second script tag will be able to import that module and use the function as usual in Python.
Importing your own code from the server
Make the files available in the appropriate place as described in the documentation. Brython's implementation of the import statement (equivalently, __import__ builtin function) will attempt to find the code on the server using AJAX.
Importing your own code as a compiled Brython package
As explained in the documentation, use the Brython package (pip install brython) to create a JavaScript file that represents the Python code. (For third-party libraries, also check if such a JavaScript file is already available from a CDN.)
Suppose we have a project that creates a package named example. Navigate to the folder that contains that package (either src or the project folder, according to how the project is organized), then run brython-cli make_package example.
This should generate a example.brython.js file. Put it somewhere on the server, and configure the server to host that file at a specific URL. Then add the corresponding tag to the client page source (or the template that generates that page).
After that it should be possible to import example, from example import ... etc. in the Brython code.
Alternately, use brython-cli modules, as described in the 'Optimization' section, to create a combined library JavaScript file representing the entire server-side part of the project.
// After the "Content-type..." declaration...
print """<html>\
<head>
<title>Create Survey</title>
<link href="styles.css" type="text/css" rel="stylesheet">
</head>
<body>...."""
Assuming you are using something like CGI to "print" text based on a web request you should rely on your web server (Apache for example) to "print" the content back to the requesting client based on where your CSS file is located in the htdocs directory.
However if you are just wanting some output in a command line window you could do...
print file('/path/to/your/file/styles.css').read()