在另一个 function 中使用来自 function 的变量，与 flask

Question

Im using Flask for making a website.

@app.route('/consulta',methods=['POST'])
def consulta():
    if request.method=='POST': #Si se han enviado datos
        dia = request.form['dia'] #Obtenemos los datos del formulario
        videobeam = request.form['videobeam']
        tablero = request.form['tablero']
        hora = request.form['hora']
        aa = darHora(hora)

        a = aa[0] #<<<<<----- HERE IS PROBLEM
        b = aa[1] #<<<<<<- HERE IS PROBLEM


        cursor = db.connection.cursor()
        cursor.execute("SELECT * FROM salones WHERE {0}=1 AND videobeam = '{2}' AND tablero = '{1}' AND `{3}` = 1 AND `{4}` = 1".format(dia,videobeam,tablero,a,b)) 

        #Buscamos que coincidan con la base de datos, se pregunta por el dia de disponibilidad, si tiene videobeam y tablero
        data = cursor.fetchall() #Se obtiene en una lista
        cursor.close() #Se cierra la conexión
        return render_template('consulta.html', datos = data) #Se visualizará los resultados, y se pasa a data como parametro

I would like to use variables 'a' and 'b' from that function, in another function, becase they came from the input from the user in a form. The problem is that i cannot "return" them, because flask only allows me to return the render_template for that function.

Any idea? Thank you!!!

Answer 1

Assuming the other function is a view function associated with a different endpoint, you can simply pass these variables using Flask session. Eg:

from flask import session

@app.route('/consulta',methods=['POST'])
def consulta():
    if request.method=='POST': #Si se han enviado datos
        dia = request.form['dia'] #Obtenemos los datos del formulario
        videobeam = request.form['videobeam']
        tablero = request.form['tablero']
        hora = request.form['hora']
        aa = darHora(hora)

        session['a'] = aa[0] #<<<<<----- HERE IS PROBLEM
        session['b'] = aa[1] #<<<<<<- HERE IS PROBLEM
        ...

 @app.route('/something')
 def user_parameters():
    a = session.get('a')
    b = session.get('b')
    ...

Answer 2

One way of handling this would be to make a and b global variables:

a = None
b = None

@app.route('/consulta',methods=['POST'])
def consulta():
    if request.method=='POST': #Si se han enviado datos
        ...
        global a, b
        a, b = aa[0], aa[1]
        ...

Now, every time consulta() gets called, the global values of a and b are replaced with new ones. Elsewhere in the program, you can do the same thing in order to get the most recently-set values of a and b .

---

Note that, if you're encountering this problem, you might want to reconsider why you need the values of a and b to act like this. Are they tied to the specific user who submitted the POST request? How are you using them in the other function, and when does the other function run relative to this one?

If you need to access the same information between various disconnected API calls, but you have a way (such as a token) to track which user is making the request, I would recommend using an actual database to store information.