[Python-checkins] cpython (merge 3.6 -> default): merge

[raymond.hettinger]

https://hg.python.org/cpython/rev/018c2e0f82c3
changeset:   105301:018c2e0f82c3
parent:      105299:8e59aff28e2a
parent:      105300:c508baa300bb
user:        Raymond Hettinger <python at rcn.com>
date:        Mon Nov 21 14:13:29 2016 -0800
summary:
  merge

files:
  Doc/library/random.rst |  13 ++++++++++---
  1 files changed, 10 insertions(+), 3 deletions(-)


diff --git a/Doc/library/random.rst b/Doc/library/random.rst
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -426,25 +426,32 @@
 
 Simulation of arrival times and service deliveries in a single server queue::
 
-    from random import gauss, expovariate
+    from random import expovariate, gauss
+    from statistics import mean, median, stdev
 
     average_arrival_interval = 5.6
     average_service_time = 5.0
     stdev_service_time = 0.5
 
     num_waiting = 0
+    arrivals = []
+    starts = []
     arrival = service_end = 0.0
     for i in range(20000):
         if arrival <= service_end:
             num_waiting += 1
             arrival += expovariate(1.0 / average_arrival_interval)
-            print(f'{arrival:6.1f} arrived')
+            arrivals.append(arrival)
         else:
             num_waiting -= 1
             service_start = service_end if num_waiting else arrival
             service_time = gauss(average_service_time, stdev_service_time)
             service_end = service_start + service_time
-            print(f'\t\t{service_start:.1f} to {service_end:.1f} serviced')
+            starts.append(service_start)
+
+    waits = [start - arrival for arrival, start in zip(arrivals, starts)]
+    print(f'Mean wait: {mean(waits):.1f}.  Stdev wait: {stdev(waits):.1f}.')
+    print(f'Median wait: {median(waits):.1f}.  Max wait: {max(waits):.1f}.')
 
 .. seealso::
 

-- 
Repository URL: https://hg.python.org/cpython