How to call a flask app after __name___ == "__main__"

Question

i'm bulding a little app that uses a small UI to take info from the user, and after all the info is entered, the user can generate a PDF with every entry stored, like this:

UI for the user to enter data

Expectec output in PDF

As you can see in the image #2 to generate the PDF, i'm using a HTML template with jinja to pass the values with the following function:

    **THIS IS A CLASS METHOD THAT RETURNS THE DATA TO GENERATE THE PDF**
    def get_datos(self):

        """
        Genera un diccionario con cada banco y la cantidad de depositos por banco
        para poder generar los PDF de los depositos
        """
        
        bancos = {}
        montos_a_depositar = [a[2] for a in (r for r in self.get_listado_de_depositos())]
        envasadoras = [str(a[3]).split(";")[0] for a in (r for r in self.get_listado_de_depositos())]
        for i in  (p for p in self.get_listado_de_depositos()):
            bancos [i[1]] = bancos.get(i[1],0)+1
        
        return (bancos,montos_a_depositar,envasadoras)



app = Flask(__name__)

@app.route("/")
def generador_depositos(banco):

        
        fecha_deposito = datetime.today().strftime("%B %d, %Y")
        #envasadora = ventana.self.get_listado_de_depositos()[0][3]
        #monto = ventana.get_listado_de_depositos()[0][2]
        return render_template(banco,fecha_deposito=fecha_deposito)

if __name__ == "__main__":

    app_window = Tk()
    app_window.geometry ("255x120")
    a_generar = ventana(app_window)

  
    app_window.mainloop()

it's still incomplete, but i hope you get idea, i want to pass the return of the get_datos function, but i don't know how to do that, if any advice on how to tackle this, would be welcome.

Answer 1

Here is very simplified version of what I did when I needed to bring some values outside of Tkinter environment:

import tkinter


class Window:
    def __init__(self, root, variable):
        self.root = root
        self.variable = variable
        self.root.mainloop()
        self.onClose()

    def onClose(self):
        self.outVariable = variable + 1

    @classmethod
    def getVariableFromWindow(cls, variable):
        root = tkinter.Tk()
        window = cls(root, variable)
        return window.outVariable

if __name__ == "__main__":
    variable = 3
    variable = Window.getVariableFromWindow(3)
    print(variable)

In your case, you would save (bancos,montos_a_depositar,envasadoras) as attributes of the object and then return those when the main loop is exited.

UPDATE: It seems like you don't really need Flask, but only the HTML it lets you render with a template. Flask uses Jinja2 to do that, and you can use it directly instead of spinning up a web app to do so, as described in this answer: render jinja2 template without a Flask context. This way you can provide variables obtained from GUI directly into render_jinja_html and get complete HTML as a return value which you can then work on converting into PDF, for example as described here: Geeks for Geeks - Python Convert Html to PDF