Hosting content as static page using Flask - python

I have a flask application that draws some HTML graphs and a Google Map.
Every time I refresh my browser it runs my index() method, which is my only method in my views.py. This method gathers the data from a set of files, and calculates the graphs, the Google Map and so forth.
This is very loading heavy and I was wondering if there's some kind of way that I can run this method whenever I do python run.py instead of calculating everything when I load my index page? I want to just save the content of my index method and show it instantly when the page is loaded, so all of the content isn't loaded when the page is refreshed.
Is this doable in any way?
Views.py
#app.route('/')
#app.route('/index')
def index():
"""Read from .json files. Generate a buttload of graphs, and data to return to index.html"""
return render_template('index.html',
trips=trips,
ids=ids,
graphJSON=graphJSON,
markerList=markerList,
routeCoordinates=routeCoordinates,
center=center)
The above makes all of the data grathering, drawing and so forth run whenever someone refreshes the page which is not my Intention. I just want to run the functions whenever the "main file" (run.py) is run and then visualize the data on my index page.

You could do the heavy loading in your __init__.py file and store the values in a variable their. Then just import it in your views.py.
For example:
__init__.py
def some_heavy_loading():
...
return values
VALUES = some_heavy_loading()
views.py
import VALUES
...
def index():
...
return render_template('index.html',
values=VALUES)

Related

Can't show html using Flask

So I have been trying to get used to Flash in python but I've come across a problem. I want that when http://localhost:5000/ is inserted in the browser a html page is displayed. I've tried multiple ways to do this like using the render_template() but that returns me a jinja2.exceptions.TemplateNotFound: index.html. I've also tried a simple return redirect() but that throws something saying the adress was not recognized or understood. When I tried using the url_for() it threw 404 - not found. I really have no idea how to fix this.
# htppserver.py
import flask
import threading
app = Flask(__name__, template_folder="Dashboard/website")
#app.route("/site", methods=["GET"])
#app.route("/", methods=["GET"])
def get_site():
return render_template("index.html")
x = threading.Thread(target=app.run)
x.start()
Currently my dir system looks something like this
main_folder # This is the working directory accordingly to os.getcwd()
├──cogs
│ └──httpserver.py # Source code is here
└──Dashboard
└website
├──...
├──index.html # This is the file I want to show
└──...
Thanks
put your html files in a folder called "templates" in the same directory as the python file that serves

Best way to create / return xlsx file to Flask?

I stuck on the problem of how to organize code / proper way to get xlsx file as output in flask app.
I have a function.py file where for now the xlsx file generates.
The sense is that flask app gets some settings in json format, these settings are processed by function that must return xlsx(?) to app.
The function do some calculations depending on the settings.
The file has the next structure:
def function (settings):
settings=settings
df = pd.read_csv(settings['df'])
from pandas import ExcelWriter
writer = ExcelWriter('file.xlsx')
if settings[somefeature1]==1:
f1=dosmth.to_excel(writer, "feature 1")
if settings[somefeature2]==1:
f2=dosmth.to_excel(writer, "feature 2")
...
writer.save()
But if the file is already generated in function, what should I pass to flask? How the flask app function must look like then (especially in case if I want to return xlsx as json)?
#app.route('/Function', methods = ['POST'])
def Function():
settings = request.get_json(force = True)
return(function(settings)) #???
You should never forget that flask is a framework for creating web applications, a web application is a piece of software that receives a web request and generates a web response.
To make it super simple: your flask function should return something that a common web browser will be able to handle.
In this case your response should return the file but also some metadata to tell to the potential receiver what is inside the response and how to handle it.
I think that something like this could work:
return send_file(filename, mimetype='application/vnd.ms-excel')

how to send data to html worksheet using flask framework

I have a function calculate_full_eva_web(input:dict) it receives input dictionary several function applied on this input to create calculations dict, after calculations i want to send this data to html dashboard and after send data to html file i can play there with jinja stuff. i am unable to do so, i tried several ways but flask throws error. and also i don't know much about ajax ,may be ajax will do my work, let me know. that is why i am tagging ajax people on this post. Traceback is also attached..Thank you
In simple words, i want to send data to html in flask ! Please check my code. Let me know if i am doing anything wrong.
imports ...
from other file import other_functions
from other file import other_functions_2
from other file import other_functions_3
app = Flask(__name__, template_folder='templates/')
#app.route("/dashboard")
def calculate_full_eva_web(input:dict):
calculate_gap = other_functions(input)
calculate_matrix = other_functions_2(input)
average = other_functions_3(input)
data = dict{'calculate_gap':calculate_gap, 'calculate_matrix':calculate_matrix,'average':average}
return render_template('pages/dashboard.html', data = data)
if __name__ == "__main__":
app.run(debug=True)
The route receive a dict as input so you must change #app.route("/dashboard") to #app.route("/dashboard/<input>") and pass input to the route in the link of the route.
For example, I have a route as below.
#app.route('/user/<name>')
def user(name):
return render_template('home.html', name=name)
To pass name to the route, I access the link http://localhost:5000/user/myname.

Python flask application not displaying generated html file for second time

I have a Python flask application which takes input id's and dynamically generates data into a html file. Below is my app.py file.
#app.route('/execute', methods=['GET', 'POST'])
def execute():
if request.method == 'POST':
id = request.form['item_ids']
list = [id]
script_output = subprocess.Popen(["python", "Search_Script.py"] + list)
# script_output = subprocess.call("python Search_Script.py "+id, shell=True)
# render_template('running.html')
script_output.communicate()
#driver = webdriver.Chrome()
#driver.get("home.html")
#driver.execute_script("document.getElementById('Executed').style.display = '';")
return render_template('execute.html')
#app.route('/output')
def output():
return render_template('output.html')
output.html file has below code at the bottom.
<div class="container" style="text-align: center;">
{% include 'itemSearchDetails.html' %}
</div>
itemSearchDetails.html is generated every time dynamically based on the input. I check for different inputs and it is generating perfectly. When I run it with some input(assume 2) values for the first time, it runs perfectly and shows the output correctly. But, when I run for different values(assume 4) for the next time, the file 'itemSearchDetails.html' is generated for those 4 values but the browser only shows output for the first 2 values. No matter how many times I run it, browser shows only output with the first run values.
So, every time only the first inputted values are shown no matter how many times I run. I am not sure if it is browser cache issue since I tried "disabling cache" in chrome. Still it didn't work. Please let me know if there is something I am missing.
Try solution from this answer:
Parameter TEMPLATES_AUTO_RELOAD
Whether to check for modifications of the template source and reload
it automatically. By default the value is None which means that Flask
checks original file only in debug mode.
Original documentation could be found here.
Looks like Jinja is caching the included template.
If you don't need to interpret the HTML as a Jinja template, but instead just include its contents as-is, read the file first and pass the contents into the template:
with open('itemSearchDetails.html', 'r') as infp:
data = infp.read()
return render_template('execute.html', data=data)
...
{{ data|safe }}
(If you do need to interpret the HTML page as Jinja (as include will), you can parse a Jinja Template out of data, then use the include tag with that dynamically compiled template.)

How to run python file from django

How I can run python file, or django file from django view.
I'm trying to make like ipython notebook, but use just text editor.
I have create view, in this view I'm simply add python(django) text.
Then when smb requests some view, wich process this python(django) file, I should send response with result.
For example, print result of query set.
In create view, I've added text:
from main.models import User
for i in User.objects.all()
print(i)
And in view I get request and send response with result of execution of code above.
If I understand well you want to run some function inside of your view that is stored in and external file. If so just put the file in your app root directory and import it in your views.py
from your_app.your_file import your_method

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