How to edit this Python code to be Shortest Job First (SJF) scheduling algorithm [Preemptive],

CAN YOU EDIT IT AND ATTACH THE RESULT ?

print("FIRST COME FIRST SERVE SCHEDULLING")

n= int(input("Enter number of processes : "))

d = dict()

for i in range(n):

key = "P"+str(i+1)

a = int(input("Enter arrival time of process"+str(i+1)+": "))

b = int(input("Enter burst time of process"+str(i+1)+": "))

l = []

l.append(a)

l.append(b)

d[key] = l

d = sorted(d.items(), key=lambda item: item[1][0])

ET = []

for i in range(len(d)):

# first process

if(i==0):

ET.append(d[i][1][1])

# get prevET + newBT

else:

ET.append(ET[i-1] + d[i][1][1])

TAT = []

for i in range(len(d)):

TAT.append(ET[i] - d[i][1][0])

WT = []

for i in range(len(d)):

WT.append(TAT[i] - d[i][1][1])

avg_WT = 0

for i in WT:

avg_WT +=i

avg_WT = (avg_WT/n)

print("Process | Arrival | Burst | Exit | Turn Around | Wait |")

for i in range(n):

print(" ",d[i][0]," | ",d[i][1][0]," | ",d[i][1][1]," | ",ET[i]," | ",TAT[i]," | ",WT[i]," | ")

print("Average Waiting Time: ",avg_WT)