In Python I would like to render a python variable "myVariable" - which is already in my workspace - to an html template with flask. I just want to render one single html page to copy paste the source code and publish that on a webserver elsewhere. My code renders local variables but I cannot find a solution for passing workspace variables to the render function.
My template (home.html):
<html>
<head>
<title>Some title</title>
</head>
<body>
<p>My variable = {{ myVariable }}. </p>
</body>
</html>
My python code:
from flask import Flask, render_template
app = Flask(__name__)
#app.route('/')
def somfun():
#myVariable = 12345 #**working... but how to use already existing workspace variable?**
return render_template("home.html", myVariable=myVariable)
if __name__ == '__main__':
app.run()
Related
I've been following multiple Flask tutorials (but mostly this one) on creating a web app that I can use to read an image into a FastAi model. At some point, I was even able to get the images to upload into a folder, but I could never get them to display on the webpage itself no matter what I tried to do (refactor the function, move the folder to 'static', explicitly declare paths, etc.). I assume I'm probably missing something incredibly basic but I don't know enough about Flask and how web apps work to know what that is.
Edit: I keep getting 400 Bad Request pages every time I attempt to upload an image through the "index.html" page and the image doesn't appear in the folder when I inspect it with Windows Explorer.
file structure:
main.py
app
--> __init__.py
--> routes.py
main.py:
from app import app
main.py:
from flask import Flask
app = Flask(__name__)
from app import routes
routes.py:
from app import app
import os
from fastai.vision.widgets import *
from flask import Flask, render_template, request
#app.route('/', methods=['GET','POST'])
def index():
return render_template('index.html')
def get_predictions(img_path):
global learner_inf
learner_inf = load_learner('app/static/model/export.pkl')
return learn_inf.predict(img_path)
#app.route('/predict', methods=['GET','POST'])
def predict():
if request.method == 'POST':
file = request.files['file']
filename = file.filename
file_path = os.path.join('app/static/uploads', filename)
file.save(file_path)
result = get_predictions(file_path)
return render_template('predict.html', result = str(result), user_image = file_path)
index.html
<!doctype html>
<html>
<head>
<title>Grocery Classifier</title>
</head>
<body>
<h1>Grocery Classifier</h1>
<form method="POST" action="/predict" enctype="multipart/form-data">
<p><input type="file" name="file /"></p>
<p><input type="submit" value="Submit"></p>
</form>
</body>
</html>
predict.html
<!doctype html>
<html>
<head>
<title>Grocery Classifier</title>
</head>
<body>
<h1>Grocery Classifier</h1>
<img src="{{ user_image }}" alt="Selected Image" class="img-thumbnail">
<h2>{{ result }}</h2>
</body>
</html>
When referencing static items such as images and files, use the static folder to hold them.
app = Flask(__name__, static_folder="static")
After that, include it in CSS/HTML. This is not the direct application of inserting images in your situation, but it serves as a good example.
background-image: url("bg.gif");
The url to reference the image can be literally anything, just be sure to remember it for later reference. The reference "bg.gif" seen in the CSS automatically does GET request to "yoururl.com/bg.gif" to obtain the image.
Now link that url to the site path.
#app.route('/bg.gif', methods=['GET'])
def bghome():
return send_from_directory("static", "bg.gif")
The route MUST be correct and exact and the file MUST exist. If you use a kwarg to get the image url, be sure to keep that url consistent to what you define in your flask backend pathing.
I have a bunch of files in a directory that I wish to render and serve to the user, but have been unable to. Going to the path always returns just the 'page_template.htm' and not the rendered file. Here's my code:
from flask import Flask, request, render_template, send_from_directory
# Instantiate the Flask app
app = Flask(__name__)
app.config.from_object(__name__)
pages = FlatPages(app)
#app.route("/")
#app.route("/index")
def index():
return render_template('index.html')
#app.route("/Special_Data/<path:path>")
def page(path):
page = send_from_directory('Special_Data', path)
return render_template('page_template.htm', page=page)
What I wish to do is to grab raw text files from the 'Special_Data' directory and to render them into html files so they look nice, then send them to the user if they click on a link.
The files are in the directory 'Special_Data' and the 'page_template.htm' is in the 'templates' directory.
Where am I going wrong?
The following example shows you how you can use FlatPages to list, display and offer files for download. The markdown code is rendered beforehand and integrated into the specified or the default template.
from flask import Flask
from flask import render_template, send_file
from flask_flatpages import FlatPages
from io import BytesIO
import os
app = Flask(__name__)
# Optional configuration here!
pages = FlatPages(app)
# ...
# List all available pages.
#app.route('/contents')
def contents():
return render_template('contents.html', pages=pages)
# Display the rendered result.
#app.route('/page/<path:path>')
def page(path):
page = pages.get_or_404(path)
template = page.meta.get('template', 'flatpage.html')
return render_template(template, page=page)
# Download the rendered result.
#app.route('/download/<path:path>')
def download(path):
page = pages.get_or_404(path)
template = page.meta.get('template', 'flatpage.html')
return send_file(
BytesIO(str(render_template(template, page=page)).encode()),
as_attachment=True,
attachment_filename=f'{os.path.basename(path)}.html'
)
templates/contents.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<ul>
{% for page in pages %}
<li>
[Download] -
{{ page.title }}
</li>
{% endfor %}
</ul>
</body>
</html>
templates/flatpage.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>{{ page.title }}</title>
</head>
<body>
{{ page }}
</body>
</html>
pages/Special_Data/ncs1.html
title: Hello
published: 2010-12-22
Hello, *World*!
Lorem ipsum dolor sit amet
If you want to use a different template for rendering, you can define one within the metadata based on the file name. Add the following below published and a suitable template within the templates folder.
template: mytemplate.html
The problem is, that send_from_directory sends the file to the client, it does not load it into memory. So your page variable is actually of type Response instead of str or a fileobject. If you want to read the file and than display it use
import werkzeug
...
#app.route("/Special_Data/<path:path>")
def page(path):
p = werkzeug.security.safe_join("Special_Data", path)
with open(p, "r", encoding="utf-8") as f:
return render_template('page_template.htm', page=f.read())
Otherwise I'm afraid I can't help as I don't know what you want to do.
Using send_from_directory Return a file to client.
So, you need to change like this
#app.route("/Special_Data/<path:path>")
def page(path):
return send_from_directory('Special_Data', path)
Or
return send_file(filename_or_fp=file_path, as_attachment=True, add_etags=True, conditional=True)
render_template will render your html template, it may return a html string. Therefore you need return file instead HTML string
Ive made a flask script which runs fine however im trying to display some values in a table on another html page which for some reason is not happening.
i've already tried going through jinja2 documentation and a few other answers but it didn't help much.
the flask file.py
from flask import Flask,render_template,request
app = Flask(__name__)
from webscraper import keeda,display_tbl
#app.route('/', methods=['POST', 'GET'])
def scraper():
if request.method == 'POST':
url = request.form['url']
df=keeda(url)
return render_template(('completed.html',display_tbl(df)))
else:
return render_template('index.html')
if __name__ == '__main__':
app.run()
the completed.html file
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Summary of Scraped Data</title>
</head>
<body>
<h1>This is what you got! </h1>
<div>
{{ display_tbl(df) }}
</div>
</body>
</html>
here's the error: jinja2.exceptions.UndefinedError: 'display_tbl' is undefined
i wanted to display a table with values on this page.
You are expecting more than what jinja2 can do for you. Please understand jinja2 is just a way to render templates which are eventually html and javascript, nothing fancy. So, in your case you cannot pass a Python function to your jinja2 template and expect that to run fine. What you can do here is to pass the data returned by display_tbl while rendering template like this:
def scraper():
...
return render_template(('completed.html', data=display_tbl(df))) # data= is important because this is how you are going to access your data in the template
…
def display_tbl(df):
… # Here you should be returning the data you want to display - a list or dict
In the template
<html>
<head>
<meta charset="UTF-8">
<title>Summary of Scraped Data</title>
</head>
<body>
<h1>This is what you got! </h1>
<div>
{{ render_data() }}
</div>
<script>
var d = data | tojson
function render_data() {
// implement the logic to handle how your data should be rendered
}
</script>
</body>
</html>
This is just a rough idea but as you can see you need to change the way you are perceiving jinja2 templates and their interaction with Python or Flask backend.
I am getting an Internal Server error, and I'm not sure what the issue is. index.html is in the same directory as the Python file.
from flask import Flask, render_template
app = Flask(__name__)
#app.route('/')
def hello_world():
author = "Rick"
name = "1st flask app"
return render_template('index.html', author=author, name=name)
if __name__ == "__main__":
app.run()
<!DOCTYPE html>
<html>
<head>
<title>{{ author }}'s app</title>
</head>
<body>
<h2>Hello {{ name }}!</h2>
<p>Please show up on the page</p>
</body>
</html>
Why am I getting a 500 error rather than my rendered template?
Create a directory called templates and put index.html in it.
You can get more information about errors by running in debug mode:
app.run(debug=True)
When you create your app
app = Flask(__name__)
you can also include the template_folder parameter to specify the folder that contains your templates. If you don't, render_template will look for them in the default folder called templates. If such folder doesn´t exist, or if your template can't be found inside it, you will get an internal server error 500 rather than your rendered template.
I want to pass a list of pages and loop it in Jinja2 to show all pages of my website. I use Flask to construct and run the app. I followed the official flask documentation, together with this tutorial. However when I try to pass the list and try to loop over it, it does not appear in the rendered html.
What am I doing wrong? How to properly pass the list and loop over it using base.html as a template?
Here is my code with a dummy page list hardcoded:
app.py:
from flask import Flask, render_template
app = Flask(__name__)
#app.route('/')
def index():
page_list = ['Eins', 'Zwei']
return render_template('base.html', pages=page_list)
if __name__ == "__main__":
app.run(port=8000)
And base.html, located in /templates/:
<html>
<head>
<title>Test</title>
</head>
<body>
<h1>All the nice pages</h1>
{% for page in pages %}
<p>{{ page }}</p>
{% endfor %}
</body>
</html>
When I run the app and browse to http://127.0.0.1:8000/, this is what I get:
<html>
<head>
<title>Test</title>
</head>
<h1>All the nice pages</h1>
<body>
</body>
</html>
This code is totally valid. The important thing is to restart the server if you do changes to lists or dictionaries.
Apart from that, in Flask you can pass any type that is built into Python, be it a list, a dictionary or a tuple.
Here are short example for each of the types that pass more or less the same content:
from flask import Flask, render_template
adictionary = {'spam': 1, 'eggs': 2}
alist = ['Eins', 'Zwei', 'Drei']
atuple = ('spam', 'eggs')
app = Flask(__name__)
#app.route('/')
def index():
return render_template('base.html', pages=alist)
#app.route('/tuple/')
def tuple():
return render_template('base.html', pages=atuple)
#app.route('/dict/')
def adict():
return render_template('base.html', pages=adictionary)
if __name__ == "__main__":
app.run(port=8000)
I was having this same issue. I use Sublime Text 3 and realized that I didn't automatically convert tabs to spaces. Once I made that change in the user settings, and reran the script, it output the list correctly.