memory 错误或 Python 中的返回列表为空

Question

The first function calculates the depth of a lake and has the volume as parameter. In the second one, I have to pass a volume and a time increment (that I have to increment) and it returns two lists. First List: time increments and the the last time/element in this list corresponds to the volume = 0, when the lake empty is. Second list: the corresponding depth to each time. For example for dt = 1000s seconds, z(depth) = 10m and for dt = 150000s, dt = 0m. Sorry, it's too much fluid mechanics, I just want to make it as clear as possible. When I call the function abfluss, it returns empty Lists when V0 is little or and it shows a memory error when v0 is bigger. I tried with many different vo and dt, I never had a filled list, it happens only when I try it without the while loop (then I have 1 element in each List). Any suggestions?

from numpy import pi
p = 0.036
def tiefe(V):
    a = (3*V*p**2)/pi
    z = a**(1/3)
    return z

U_unten = 35.56
A = 2                                                                       
def abfluss(V0, dt):
    
    V_geblieben = V0 - (U_unten*A*dt)/V0
    neu_tiefe = tiefe(V_geblieben)
    t_list = []
    Z_list = []
    while V_geblieben >=0:
        dt = dt+100
        t_list.append(dt)
        Z_list.append(neu_tiefe)
     
    return  t_list, Z_list
print(abfluss(50000,3600))

Answer 1

recalculate V_geblieben inside loop and it works

from math import pi

p = 0.036


def tiefe(V):
    a = (3 * V * p ** 2) / pi
    z = a ** (1 / 3)
    return z


U_unten = 35.56
A = 2


def abfluss(V0, dt):
    V_geblieben = V0 - (U_unten * A * dt) / V0
    neu_tiefe = tiefe(V_geblieben)
    t_list = []
    Z_list = []
    while V_geblieben >= 0:
        dt = dt + 100
        t_list.append(dt)
        Z_list.append(neu_tiefe)
        V_geblieben = V0 - (U_unten * A * dt) / V0
        print(V_geblieben)
    return t_list, Z_list


print(abfluss(50000, 3600))

Answer 2

this returns two lists from the function. I made numerous changes to the code, please let me know if you have any questions about the code.

 ##This program outputs the depth of a draining lake at different time intervals
    ##Imports 
    from math import *
    ##Function                                                                     
    def abfluss(V0,dt):##functon that takes the intial volume of the lake and a time interval 
        t_list = []
        Z_list = []
        while V0 >=0:
            z= ((3*V0*0.036**2)/pi)**(1/3)
            t_list.append(dt)
            Z_list.append(z)
            U_unten = 35.56 
            V0 = V0 - (U_unten*2*dt)/V0
            dt = dt+0.01
        return  t_list, Z_list
    ##Main Program 
    V0 = float(input('Please enter an initail volume for the lake:')) ##Take initial lake volume from user in *define units for volume*
    dt = float(input('Please enter a time interval for dt:'))
    res_abfluss = abfluss(V0,dt) ##passes the user inputs to the finction 
    print(res_abfluss) ##prints the two resulting of the lists of the fucniton