wrapping python code in main()

The code will not give error on Windows OS if wrapped inside the main function.

Chapter07/multiprocessing/process1.py

@@ -12,6 +12,7 @@ def print_message(msg):
     sleep(1)
     print("{}-{}: {}".format(os.getpid(), cp().name, msg))
 
+def main():
     processes = []
 
     # creating process
@@ -29,3 +30,6 @@ for p in processes:
         p.join()
 
     print("Exiting the main process")
+
+if __name__ == '__main__':
+    main()

Chapter07/multiprocessing/process2.py

@@ -7,9 +7,14 @@ def print_message(msg):
     sleep(1)
     print("{}-{}: {}".format(os.getpid(), cp().name, msg))
 
+
+def main():
     # creating process from a pool
     with Pool(3) as proc:
         proc.map(print_message, ["Orange", "Apple", "Banana",
                                  "Grapes","Pears"])
 
     print("Exiting the main process")
+
+if __name__ == '__main__':
+    main()

Chapter07/multiprocessing/process3.py

@@ -10,6 +10,7 @@ def inc_sum_list(list, inc_list, sum):
         inc_list[index] = num + 1
         sum.value = sum.value + inc_list[index]
 
+def main():
 
     mylist = [2, 5, 7]
 
@@ -26,3 +27,6 @@ print("incremented list: ", list(inc_list))
     print("sum of inc list: ", sum.value)
 
     print("Exiting the main process")
+
+if __name__ == '__main__':
+    main()

Chapter07/multiprocessing/process4.py

@@ -9,6 +9,7 @@ def insert_data (dict1, code, subject):
 def output(dict1):
     print("Dictionary data: ", dict1)
 
+def main():
     with multiprocessing.Manager() as mgr:
         # create a dictionary in the server process
         mydict = mgr.dict({100: "Maths", 200: "Science"})
@@ -27,3 +28,6 @@ with multiprocessing.Manager() as mgr:
         p3.join()
 
     print("Exiting the main process")
+
+if __name__ == '__main__':
+    main()

Chapter07/multiprocessing/process5.py

@@ -11,6 +11,7 @@ def output(myqueue):
     while not myqueue.empty():
         print(myqueue.get())
 
+def main():
     mylist = [2, 5, 7]
     myqueue = Queue()
 
@@ -24,3 +25,6 @@ p2.join()
 
     print("Queue is empty: ",myqueue.empty())
     print("Exiting the main process")
+
+if __name__ == '__main__':
+    main()

Chapter07/multiprocessing/process6.py

@@ -15,6 +15,8 @@ def myreceiver(r_conn):
             break
         print("Received message : ", msg)
     r_conn.close()
+
+def main():
     sender_conn, receiver_conn= Pipe()
 
     p1 = Process(target=mysender, args=(sender_conn, ))
@@ -27,3 +29,6 @@ p1.join()
     p2.join()
 
     print("Exiting the main process")
+
+if __name__ == '__main__':
+    main()

Chapter07/multiprocessing/process7.py

@@ -9,6 +9,7 @@ def printme (lock, msg):
     finally:
         lock.release()
 
+def main():
     with Pool(3) as proc:
         lock = Manager().Lock()
         func = partial(printme,lock)
@@ -16,3 +17,6 @@ with Pool(3) as proc:
                                  "Grapes","Pears"])
 
     print("Exiting the main process")
+
+if __name__ == '__main__':
+    main()