1. def findWaitingTime(processes, n, bt,  wt, quantum):  
2.  
3.     rem_bt = [0] * n
4.  
5.   # Copy the burst time into rt[]  
6.  
7.     for i in range(n):  
8.  
9.         rem_bt[i] = bt[i]
10.  
11.     t = 0 # Current time  
12.  
13.  
14.  
15.     # Keep traversing processes in round  
16.  
17.     # robin manner until all of them are
18.  
19.     # not done.  
20.  
21.     while(1):
22.  
23.         done = True
24.  
25.  
26.  
27.         # Traverse all processes one by
28.  
29.         # one repeatedly  
30.  
31.         for i in range(n):
32.  
33.              
34.  
35.             # If burst time of a process is greater  
36.  
37.             # than 0 then only need to process further  
38.  
39.             if (rem_bt[i] > 0) :
40.  
41.                 done = False # There is a pending process
42.  
43.                  
44.  
45.                 if (rem_bt[i] > quantum) :
46.  
47.                  
48.  
49.                     # Increase the value of t i.e. shows  
50.  
51.                     # how much time a process has been processed  
52.  
53.                     t += quantum  
54.  
55.  
56.  
57.                     # Decrease the burst_time of current  
58.  
59.                     # process by quantum  
60.  
61.                     rem_bt[i] -= quantum  
62.  
63.                  
64.  
65.                 # If burst time is smaller than or equal  
66.  
67.                 # to quantum. Last cycle for this process  
68.  
69.                 else:
70.  
71.                  
72.  
73.                     # Increase the value of t i.e. shows  
74.  
75.                     # how much time a process has been processed  
76.  
77.                     t = t + rem_bt[i]  
78.  
79.  
80.  
81.                     # Waiting time is current time minus  
82.  
83.                     # time used by this process  
84.  
85.                     wt[i] = t - bt[i]  
86.  
87.  
88.  
89.                     # As the process gets fully executed  
90.  
91.                     # make its remaining burst time = 0  
92.  
93.                     rem_bt[i] = 0
94.  
95.                  
96.  
97.         # If all processes are done  
98.  
99.         if (done == True):
100.  
101.             break
102.  
103.              
104. # Function to calculate turn around time  
105.  
106. def findTurnAroundTime(processes, n, bt, wt, tat):
107.  
108.      
109.  
110.     # Calculating turnaround time  
111.  
112.     for i in range(n):
113.  
114.         tat[i] = bt[i] + wt[i]  
115.  
116.  
117.  
118.  
119. # Function to calculate average waiting  
120. # and turn-around times.  
121.  
122. def findavgTime(processes, n, bt, quantum):  
123.  
124.     wt = [0] * n
125.  
126.     tat = [0] * n  
127.  
128.  
129.  
130.     # Function to find waiting time
131.  
132.     # of all processes  
133.  
134.     findWaitingTime(processes, n, bt,  
135.  
136.                          wt, quantum)  
137.  
138.  
139.  
140.     # Function to find turn around time
141.  
142.     # for all processes  
143.  
144.     findTurnAroundTime(processes, n, bt,
145.  
146.                                 wt, tat)  
147.  
148.  
149.  
150.     # Display processes along with all details  
151.  
152.     print("Processes    Burst Time     Waiting",  
153.  
154.                      "Time    Turn-Around Time")
155.  
156.     total_wt = 0
157.  
158.     total_tat = 0
159.  
160.     for i in range(n):
161.  
162.  
163.  
164.         total_wt = total_wt + wt[i]  
165.  
166.         total_tat = total_tat + tat[i]  
167.  
168.         print(" ", proc[i], "\t\t", bt[i],  
169.  
170.               "\t\t", wt[i], "\t\t", tat[i])
171.  
172.  
173.  
174.     print("\nAverage waiting time = %.5f "%(total_wt /n) )
175.  
176.     print("Average turn around time = %.5f "% (total_tat / n))  
177.  
178.      
179. # Driver code  
180.  
181. if __name__ =="__main__":
182.  
183.      
184.  
185.     # Process id's  
186.  
187.     proc = ["p1","p2", "p3"]
188.  
189.     n = 3
190.  
191.  
192.  
193.     # Burst time of all processes  
194.  
195.     burst_time = [10, 5, 8]  
196.  
197.  
198.  
199.     # Time quantum  
200.  
201.     quantum = 2;  
202.  
203.     findavgTime(proc, n, burst_time, quantum)
204.  
205.  
206. # This code is contributed by
207. # Shubham Singh(SHUBHAMSINGH10