def main():
    usingJSON = False
    al = []
    print('==Exercise 3==')
    if not usingJSON: 
        print('''I have a method to input all 5 floats in one time using JSON.
            Pls set usingJSON = True in source code to try it.''')
        for i in range(5):
            flag=True
            while flag:
                a = input(f"pls input float {i+1}:")
                try: 
                    a = float(a)
                    flag=False
                    al.append(a)
                except :
                    print("pls input a float!")
        print(al)
    else:
        import json
        print("In this case you need to enter a JSON string of the whole list.")
        flag=True
        while flag:
            a = input("pls input float[] JSON:")
            try: 
                a = json.loads(a)
                states = [True if type(i)==float else False for i in a]
                if False in states:
                    print(f"Error! not a float[]!\nCurrent Input:{a}")
                    raise ValueError("Not a float[]")
                flag=False
                al.append(a)
            except :
                print("pls input a proper float[]!")
    print('==End Of Ex3==')
    return 0

if __name__ == '__main__':
    main()