What does happen if seed value is not declared throughout in a python code?

import random 
import matplotlib.pyplot as plt 
 
nums = [] 

mu = 0
sigma = 2
    
for i in range(100): 
    temp = random.gauss(mu, sigma)
    nums.append(temp) 
         
plt.plot(nums) 
plt.show()

Here, I haven't declared the seed value. So, will it consider different seed values at each iterations of i ? In this kind of simulations or say in long monte carlo simulations is it reccomened to chose different values of seeds instead of a particular fixed seed value ?