Exiting while loop correctly with return statement-CodePudding

I have this while loop within one of my Flask routes. The purpose of the function is to retrieve a value from the user and check if that str exists in any filenames within a directory. If true, return "plot_list" and exit function. If false, wait 30 seconds and then check again if that str exists in any filenames within a directory.

@app.route("/data")
def datatable():
    selected_project = str(request.args.get('selected_project'))
    csv_path = "..\static\csv\dist_drift"

    start_time = time.time()
    while True:
        time.sleep(5)
        for fname in os.listdir(csv_path):
            if selected_project in fname:
                print("{} csv was found in {}".format(selected_project, csv_path))
                plot_list = ["basketball.html", "hockey.html"]
                return jsonify(plot_list)

            else:
                current_time = time.time()
                print("{} csv not found in {} after waiting {} seconds!".format(selected_project, csv_path,
                                                                                (current_time - start_time)))
                time.sleep(30)

These are the print statements from the function:

Advanced csv was found in \static\csv\dist_drift
None csv not found in \static\csv\dist_drift after waiting 5.001329660415649 seconds!
["basketball.html", "hockey.html"]
None csv not found in \static\csv\dist_drift after waiting 35.00231146812439 seconds!
None csv not found in \static\csv\dist_drift after waiting 65.00326824188232 seconds!

I'm sure this is an easy fix, but I can't figure it out. Any help?

Edit: The problem is that the function isn't exiting even though the str exists in filenames within the directory.

CodePudding user response：

Your return outside the function. Just fix tabs

@app.route("/data")
def datatable():
    selected_project = str(request.args.get('selected_Project'))
    csv_path = "..\static\csv\dist_drift"

    start_time = time.time()
    time.sleep(5)
    while True:
        for fname in os.listdir(csv_path):
            if selected_project in fname:
                print("{} csv was found in {}".format(selected_project , csv_path))
                plot_list = ["basketball.html", "hockey.html"]
                print(plot_list)
                return jsonify(plot_list)
        else:
            current_time = time.time()
            print("{} csv not found in {} after waiting {} seconds!".format(selected_project , csv_path,
                                                                            (current_time - start_time)))
            time.sleep(30)

CodePudding user response：

you just need to use "break" {break is a simple way to exit a loop} the fixed version of your code is :

@app.route("/data")
def datatable():
    selected_project = str(request.args.get('selected_Project'))
    csv_path = "..\static\csv\dist_drift"

    start_time = time.time()
    time.sleep(5)
    while True:
        for fname in os.listdir(csv_path):
            if selected_project in fname:
                print("{} csv was found in {}".format(selected_project , csv_path))
                plot_list = ["basketball.html", "hockey.html"]
                print(plot_list)
                break
        else:
            current_time = time.time()
            print("{} csv not found in {} after waiting {} seconds!".format(selected_project , csv_path,
                                                                            (current_time - start_time)))
            time.sleep(30)
    return jsonify(plot_list)