first time use plot - I get empty graph

[korenron]

how can I do this?

how do I Plot the entire list with one call to plot() ?

import matplotlib.pyplot as plt

def GetDataFunction()
   t= 0
   while t <250:
       Speed = GetData()
       print(f"Speed: {Speed} Km/h ")
       plt.plot(t, float(Speed))
       t += 1
 
GetDataFunction()
 
plt.show()

Thanks ,