From ebeec917906bb0c9b6cdd987e60dd06841571264 Mon Sep 17 00:00:00 2001
From: Luciano Ramalho <luciano@ramalho.org>
Date: Wed, 20 Jan 2021 23:19:20 -0300
Subject: [PATCH] Python 3.7 example without some types

---
 20-concurrency/primes/procs_py37.py | 43 +++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 20-concurrency/primes/procs_py37.py

diff --git a/20-concurrency/primes/procs_py37.py b/20-concurrency/primes/procs_py37.py
new file mode 100644
index 0000000..c786e9d
--- /dev/null
+++ b/20-concurrency/primes/procs_py37.py
@@ -0,0 +1,43 @@
+# tag::PRIMES_PROC_TOP[]
+from time import perf_counter
+from typing import Tuple, List, NamedTuple
+from multiprocessing import Process, SimpleQueue  # <1>
+
+from primes import is_prime, NUMBERS
+
+class Result(NamedTuple):  # <3>
+    flag: bool
+    elapsed: float
+
+def check(n: int) -> Result:  # <5>
+    t0 = perf_counter()
+    res = is_prime(n)
+    return Result(res, perf_counter() - t0)
+
+def job(n: int, results) -> None:  # <6>
+    results.put((n, check(n)))  # <7>
+# end::PRIMES_PROC_TOP[]
+
+# tag::PRIMES_PROC_MAIN[]
+def main() -> None:
+    t0 = perf_counter()
+    results = SimpleQueue()  # <1>
+    workers: List[Process] = []  # <2>
+
+    for n in NUMBERS:
+        worker = Process(target=job, args=(n, results))  # <3>
+        worker.start()  # <4>
+        workers.append(worker)  # <5>
+
+    for _ in workers:  # <6>
+        n, (prime, elapsed) = results.get()  # <7>
+        label = 'P' if prime else ' '
+        print(f'{n:16}  {label} {elapsed:9.6f}s')
+
+
+    time = perf_counter() - t0
+    print('Total time:', f'{time:0.2f}s')
+
+if __name__ == '__main__':
+    main()
+# end::PRIMES_PROC_MAIN[]