Draw chart for rolling dice for k times

rolldice.py

import random
import matplotlib.pyplot as plt

#How many times do you want the loop to run?
howmanytimes = 1000000
k = 4
def dice():
    r = ''
    for j in range(0,k):
        r += str(random.randint(1,6))
    return r

x = []
for i in range(0,howmanytimes):
    x.append(dice())

d = {}
for i in range(k,k*6+1):
    d[i] = 0

for i in x:
    t = 0
    for j in range(0,len(i)):
        t += int(i[j])
    d[t] += 1
for i in d:
    d[i] = d[i]/len(x)

sumofprobabilities = 0
for i in d:
    sumofprobabilities += d[i]

expectedvalue = 0
for i in d:
    expectedvalue += d[i]*i
print(d)
print("Sum of Probabilities:", sumofprobabilities)
print("Expected Value:", expectedvalue)

plt.bar(range(len(d)), list(d.values()), align='center')
plt.xticks(range(len(d)), list(d.keys()))
plt.suptitle('If we roll the dice '+str(k)+' times')
plt.show()