Updated code examples for paperback version

Author: SuperFastPython

README.md

@@ -20,11 +20,11 @@ You can learn more about the book here:
 
 * [Gumroad](https://superfastpython.gumroad.com/l/pmpj)
 * [Amazon](https://www.amazon.com/dp/B0B6YSF8XQ)
-* [GoodReads](https://www.goodreads.com/book/show/61606103-python-multiprocessing-pool-jump-start)
+* [Goodreads](https://www.goodreads.com/book/show/61606103-python-multiprocessing-pool-jump-start)
 
 ### Book Blurb
 
-> How much faster can your python code run (if it used all CPU cores)?
+> How much faster could your python code run (if it used all CPU cores)?
 >
 > The multiprocessing.Pool class provides easy-to-use process-based concurrency.
 >
@@ -42,7 +42,6 @@ You can learn more about the book here:
 >
 > Each lesson ends with an exercise for you to complete to confirm you understood the topic, a summary of what was learned, and links for further reading if you want to go deeper.
 >
-> Stop copy-pasting code from outdated blog posts.
-> Stop trying to parse messy StackOverflow answers.
+> Stop copy-pasting code from outdated StackOverflow answers.
 >
 > Learn Python concurrency correctly, step-by-step.

src/lesson01_pool.py

@@ -1,5 +1,5 @@
 # SuperFastPython.com
-# example of running a function in the multiprocessing pool
+# example running a function in the multiprocessing pool
 from multiprocessing import Pool
 
 # a task to execute in another process

src/lesson02_default.py

@@ -1,10 +1,10 @@
 # SuperFastPython.com
-# example of reporting the details of a default multiprocessing pool
+# example reporting the details of a default pool
 from multiprocessing import Pool
 
 # protect the entry point
 if __name__ == '__main__':
-    # create a multiprocessing pool with the default number of workers
+    # create a multiprocessing pool
     pool = Pool()
     # report the status of the multiprocessing pool
     print(pool)

src/lesson02_initalizer.py

@@ -1,5 +1,5 @@
 # SuperFastPython.com
-# example of initializing worker processes in the multiprocessing pool
+# example initializing worker processes in the pool
 from time import sleep
 from multiprocessing import Pool
 

src/lesson03_map.py

@@ -5,14 +5,14 @@
 # a task to execute in another process
 def task(arg):
     # report a message
-    print(f'This is another process with {arg}', flush=True)
+    print(f'From another process {arg}', flush=True)
     # return a value
     return arg * 2
 
 # entry point for the program
 if __name__ == '__main__':
     # create the multiprocessing pool
     with Pool() as pool:
-        # issue multiple tasks to the pool and process return values
+        # issue multiple tasks and process return values
         for result in pool.map(task, range(10)):
             print(result)

src/lesson03_starmap.py

@@ -1,11 +1,12 @@
 # SuperFastPython.com
-# example of executing multiple tasks with multiple arguments
+# example of multiple tasks with multiple arguments
 from multiprocessing import Pool
 
 # a task to execute in another process
 def task(arg1, arg2, arg3):
     # report a message
-    print(f'This is another process with {arg1}, {arg2}, {arg3}', flush=True)
+    print(f'From another process {arg1}, {arg2}, {arg3}',
+        flush=True)
     # return a value
     return arg1 + arg2 + arg3
 
@@ -15,6 +16,6 @@ def task(arg1, arg2, arg3):
     with Pool() as pool:
         # prepare task arguments
         args = [(i, i*2, i*3) for i in range(10)]
-        # issue multiple tasks to the pool and process return values
+        # issue multiple tasks and process return values
         for result in pool.starmap(task, args):
             print(result)

src/lesson04_map_async.py

@@ -1,11 +1,11 @@
 # SuperFastPython.com
-# example of executing multiple task with Pool.map_async()
+# example executing multiple task with Pool.map_async()
 from multiprocessing import Pool
 
 # a task to execute in another process
 def task(arg):
     # report a message
-    print(f'This is another process with {arg}', flush=True)
+    print(f'From another process {arg}', flush=True)
     # return a value
     return arg * 2
 
@@ -15,6 +15,6 @@ def task(arg):
     with Pool() as pool:
         # issue multiple tasks to the pool
         async_result = pool.map_async(task, range(10))
-        # process return values once all issued tasks have completed
+        # process return values once all tasks completed
         for result in async_result.get():
             print(result)

src/lesson04_starmap_async.py

@@ -1,11 +1,12 @@
 # SuperFastPython.com
-# example of executing multiple tasks with multiple arguments
+# example with multiple tasks with multiple arguments
 from multiprocessing import Pool
 
 # a task to execute in another process
 def task(arg1, arg2, arg3):
     # report a message
-    print(f'This is another process with {arg1}, {arg2}, {arg3}', flush=True)
+    print(f'From another process {arg1}, {arg2}, {arg3}',
+        flush=True)
     # return a value
     return arg1 + arg2 + arg3
 

src/lesson05_imap.py

@@ -9,14 +9,14 @@ def task(arg):
     # block for a random fraction of a second
     sleep(random())
     # report a message
-    print(f'This is another process with {arg}', flush=True)
+    print(f'From another process {arg}', flush=True)
     # return a value
     return arg * 2
 
 # entry point for the program
 if __name__ == '__main__':
     # create the multiprocessing pool
     with Pool(4) as pool:
-        # issue multiple tasks to the pool and process return values
+        # issue multiple tasks and process return values
         for result in pool.imap(task, range(10)):
             print(result)

src/lesson05_imap_unordered.py

@@ -1,5 +1,5 @@
 # SuperFastPython.com
-# example of executing multiple task with Pool.imap_unordered()
+# example executing multiple task with imap_unordered()
 from time import sleep
 from random import random
 from multiprocessing import Pool
@@ -9,14 +9,14 @@ def task(arg):
     # block for a random fraction of a second
     sleep(random())
     # report a message
-    print(f'This is another process with {arg}', flush=True)
+    print(f'From another process {arg}', flush=True)
     # return a value
     return arg * 2
 
 # entry point for the program
 if __name__ == '__main__':
     # create the multiprocessing pool
     with Pool(4) as pool:
-        # issue multiple tasks to the pool and process return values
-        for result in pool.imap_unordered(task, range(10)):
-            print(result)
+        # issue multiple tasks and process return values
+        for rs in pool.imap_unordered(task, range(10)):
+            print(rs)

src/lesson06_asyncresult.py

@@ -1,5 +1,5 @@
 # SuperFastPython.com
-# example of checking the status and handling the result of an async task
+# example check status and handle result of async task
 from time import sleep
 from random import random
 from multiprocessing import Pool

src/lesson06_callback.py

@@ -13,7 +13,8 @@ def task(identifier):
     # generate a value
     value = random()
     # report a message
-    print(f'Task {identifier} executing with {value}', flush=True)
+    print(f'Task {identifier} executing with {value}',
+        flush=True)
     # block for a moment
     sleep(value)
     # return the generated value
@@ -24,7 +25,8 @@ def task(identifier):
     # create and configure the multiprocessing pool
     with Pool() as pool:
         # issue tasks to the multiprocessing pool
-        result = pool.apply_async(task, args=(0,), callback=result_callback)
+        result = pool.apply_async(task, args=(0,),
+            callback=result_callback)
         # close the multiprocessing pool
         pool.close()
         # wait for all tasks to complete

src/lesson07_check_prime_parallel.py

@@ -1,5 +1,5 @@
 # SuperFastPython.com
-# check if large numbers are prime concurrently with Pool.imap()
+# check if large numbers are prime concurrently
 from math import sqrt
 from math import floor
 from multiprocessing import Pool
@@ -15,9 +15,9 @@ def is_prime(number):
     # check if the number divides by 2 with no remainder
     if number % 2 == 0:
         return False
-    # limit on divisors we test, sqrt of n, +1 so range() will reach it
+    # limit divisors to sqrt(n)+1 so range will reach it
     limit = floor(sqrt(number)) + 1
-    # check for evenly divisible for odd numbers between 3 and sqrt(n)
+    # check all odd numbers in range
     for i in range(3, limit, 2):
         # check if number is divisible with no remainder
         if number % i == 0:
@@ -40,9 +40,11 @@ def check_numbers_are_prime(numbers):
 # entry point
 if __name__ == '__main__':
     # define some numbers to check
-    NUMS = [17977, 10619863, 106198, 6620830889, 80630964769, 228204732751,
-        1171432692373, 1398341745571, 10963707205259, 15285151248481,
-        99999199999, 304250263527209, 30425026352720, 10657331232548839,
-        10657331232548830,  44560482149, 1746860020068409]
+    NUMS = [17977, 10619863, 106198, 6620830889,
+        80630964769, 228204732751, 1171432692373,
+        1398341745571, 10963707205259, 15285151248481,
+        99999199999, 304250263527209, 30425026352720,
+        10657331232548839, 10657331232548830,
+        44560482149, 1746860020068409]
     # check whether each number is a prime
     check_numbers_are_prime(NUMS)

src/lesson07_check_prime_sequential.py

@@ -14,9 +14,9 @@ def is_prime(number):
     # check if the number divides by 2 with no remainder
     if number % 2 == 0:
         return False
-    # limit on divisors we test, sqrt of n, +1 so range() will reach it
+    # limit divisors to sqrt(n)+1 so range will reach it
     limit = floor(sqrt(number)) + 1
-    # check for evenly divisible for odd numbers between 3 and sqrt(n)
+    # check all odd numbers in range
     for i in range(3, limit, 2):
         # check if number is divisible with no remainder
         if number % i == 0:
@@ -35,9 +35,12 @@ def check_numbers_are_prime(numbers):
 # entry point
 if __name__ == '__main__':
     # define some numbers to check
-    NUMS = [17977, 10619863, 106198, 6620830889, 80630964769, 228204732751,
-        1171432692373, 1398341745571, 10963707205259, 15285151248481,
-        99999199999, 304250263527209, 30425026352720, 10657331232548839,
-        10657331232548830,  44560482149, 1746860020068409]
+    NUMS = [17977, 10619863, 106198, 6620830889,
+        80630964769, 228204732751, 1171432692373,
+        1398341745571, 10963707205259, 15285151248481,
+        99999199999, 304250263527209, 30425026352720,
+        10657331232548839, 10657331232548830,
+        44560482149, 1746860020068409]
     # check whether each number is a prime
     check_numbers_are_prime(NUMS)
+