update

2020.06.01_parallel_calculations_with_python/application_of_parallel_calculations_with_python.py

@@ -3,7 +3,7 @@ This code is supported by the website: https://www.guanjihuan.com
 The newest version of this code is on the web page: https://www.guanjihuan.com/archives/4536
 """
 
-from multiprocessing import Process
+import multiprocessing
 import os
 import time
 import numpy as np
@@ -25,13 +25,14 @@ if __name__ == '__main__':
     process_array = []
     for task_index in range(task_num):
         parameter_array = guan.preprocess_for_parallel_calculations(parameter_array_all, task_num, task_index)
-        process_array.append(Process(target=main, args=(parameter_array, task_index)))
+        process_array.append(multiprocessing.Process(target=main, args=(parameter_array, task_index)))
     for process in process_array: # 运行子进程
         process.start()
     for process in process_array: # 等待子进程完成
         process.join() 
     end_time = time.perf_counter()
-    print('运行时间=', (end_time-start_time), '\n')
+    print('运行时间=', (end_time-start_time))
+    # 合并数据
     f = open('result.txt', 'w')
     for task_index in range(task_num):
         with open('task_index='+str(task_index)+'.txt', 'r') as f0:

2020.06.01_parallel_calculations_with_python/parallel_calculations_with_python.py

@@ -3,7 +3,7 @@ This code is supported by the website: https://www.guanjihuan.com
 The newest version of this code is on the web page: https://www.guanjihuan.com/archives/4536
 """
 
-from multiprocessing import Process
+import multiprocessing
 import os
 import time
 
@@ -31,10 +31,10 @@ if __name__ == '__main__':
     print('并行程序')
     print('Process id = %s.' % os.getpid())
     start_time = time.perf_counter()
-    p1 = Process(target=run_proc, args=('job1',))
-    p2 = Process(target=run_proc, args=('job2',))
-    p3 = Process(target=run_proc, args=('job3',))
-    p4 = Process(target=run_proc, args=('job4',))
+    p1 = multiprocessing.Process(target=run_proc, args=('job1',))
+    p2 = multiprocessing.Process(target=run_proc, args=('job2',))
+    p3 = multiprocessing.Process(target=run_proc, args=('job3',))
+    p4 = multiprocessing.Process(target=run_proc, args=('job4',))
     p1.start()
     p2.start()
     p3.start()

2020.06.01_parallel_calculations_with_python/parallel_calculations_with_python_using_Value.py

@@ -3,16 +3,16 @@ This code is supported by the website: https://www.guanjihuan.com
 The newest version of this code is on the web page: https://www.guanjihuan.com/archives/4536
 """
 
-from multiprocessing import Process, Value
+import multiprocessing
 
 def run_proc(name, a, num): # 要执行的代码
     num.value = a
 
 if __name__ == '__main__':
-    num1 = Value('d', 0.0)  # 共享内存
-    num2 = Value('d', 0.0)  # 共享内存
-    p1 = Process(target=run_proc, args=('job1', 100, num1))
-    p2 = Process(target=run_proc, args=('job2', 200, num2))
+    num1 = multiprocessing.Value('d', 0.0)  # 共享内存
+    num2 = multiprocessing.Value('d', 0.0)  # 共享内存
+    p1 = multiprocessing.Process(target=run_proc, args=('job1', 100, num1))
+    p2 = multiprocessing.Process(target=run_proc, args=('job2', 200, num2))
     p1.start()
     p2.start()
     p1.join()

2020.06.01_parallel_calculations_with_python/parallel_calculations_with_python_using_kwargs.py

@@ -0,0 +1,35 @@
+"""
+This code is supported by the website: https://www.guanjihuan.com
+The newest version of this code is on the web page: https://www.guanjihuan.com/archives/4536
+"""
+
+from multiprocessing import Process
+import os
+import time
+
+def run_proc(name, a=0, b=-1): # 要执行的代码
+    start_time = time.perf_counter()
+    time.sleep(2)
+    end_time = time.perf_counter()
+    print ('Process id running on %s = %s' % (name, os.getpid()), f'; Values: a={a}, b={b}', '; running time = %s' % (end_time-start_time))
+
+
+if __name__ == '__main__':
+
+    print('并行程序')
+    print('Process id = %s.' % os.getpid())
+    start_time = time.perf_counter()
+    p1 = Process(target=run_proc, kwargs={'name':'job1', 'a':10, 'b':100})
+    p2 = Process(target=run_proc, kwargs={'name':'job2', 'a':20})
+    p3 = Process(target=run_proc, kwargs={'name':'job3', 'b':300})
+    p4 = Process(target=run_proc, kwargs={'name':'job4'})
+    p1.start()
+    p2.start()
+    p3.start()
+    p4.start()
+    p1.join()  # join()方法可以等待子进程结束后再继续往下运行
+    p2.join()  
+    p3.join()  
+    p4.join()
+    end_time = time.perf_counter()
+    print('运行时间(s)=', (end_time-start_time))