update from atlas

17-futures/crypto/arcfour-timings.txt

@@ -0,0 +1,65 @@
+workers|time
+4|4.96
+3|5.40
+2|8.35
+1|11.25
+1|11.17
+2|8.45
+3|6.08
+4|5.83
+4|6.22
+3|7.33
+2|9.48
+1|11.86
+1|11.72
+2|9.22
+3|6.74
+4|6.37
+4|4.94
+3|5.51
+2|8.25
+1|11.47
+1|12.90
+2|8.94
+3|6.44
+4|5.90
+4|5.94
+3|6.46
+2|9.10
+1|11.66
+1|11.48
+2|9.08
+3|6.31
+4|5.99
+4|5.02
+3|5.46
+2|8.26
+1|11.18
+1|11.23
+2|8.52
+3|5.64
+4|5.39
+4|5.53
+3|6.07
+2|8.66
+1|11.42
+1|11.34
+2|8.44
+3|5.88
+4|5.57
+4|4.93
+3|5.47
+2|8.65
+1|11.23
+1|11.12
+2|7.83
+3|5.81
+4|5.45
+4|5.54
+3|6.09
+2|8.84
+1|11.45
+1|11.25
+2|8.32
+3|6.02
+4|5.74

17-futures/crypto/arcfour.py

@@ -0,0 +1,55 @@
+"""RC4 compatible algorithm"""
+
+def arcfour(key, in_bytes, loops=20):
+
+    kbox = bytearray(256)  # create key box
+    for i, car in enumerate(key):  # copy key and vector
+        kbox[i] = car
+    j = len(key)
+    for i in range(j, 256):  # repeat until full
+        kbox[i] = kbox[i-j]
+
+    # [1] initialize sbox
+    sbox = bytearray(range(256))
+
+    # repeat sbox mixing loop, as recommened in CipherSaber-2
+    # http://ciphersaber.gurus.com/faq.html#cs2
+    j = 0
+    for k in range(loops):
+        for i in range(256):
+            j = (j + sbox[i] + kbox[i]) % 256
+            sbox[i], sbox[j] = sbox[j], sbox[i]
+
+    # main loop
+    i = 0
+    j = 0
+    out_bytes = bytearray()
+
+    for car in in_bytes:
+        i = (i + 1) % 256
+        # [2] shuffle sbox
+        j = (j + sbox[i]) % 256
+        sbox[i], sbox[j] = sbox[j], sbox[i]
+        # [3] compute t
+        t = (sbox[i] + sbox[j]) % 256
+        k = sbox[t]
+        car = car ^ k
+        out_bytes.append(car)
+
+    return out_bytes
+
+
+def test():
+    from time import time
+    clear = bytearray(b'1234567890' * 100000)
+    t0 = time()
+    cipher = arcfour(b'key', clear)
+    print('elapsed time: %.2fs' % (time() - t0))
+    result = arcfour(b'key', cipher)
+    assert result == clear, '%r != %r' % (result, clear)
+    print('elapsed time: %.2fs' % (time() - t0))
+    print('OK')
+
+
+if __name__ == '__main__':
+    test()

17-futures/crypto/arcfour_futures.py

@@ -0,0 +1,46 @@
+import sys
+import time
+from concurrent import futures
+from random import randrange
+from arcfour import arcfour
+
+JOBS = 12
+SIZE = 2**18
+
+KEY = b"'Twas brillig, and the slithy toves\nDid gyre"
+STATUS = '{} workers, elapsed time: {:.2f}s'
+
+
+def arcfour_test(size, key):
+    in_text = bytearray(randrange(256) for i in range(size))
+    cypher_text = arcfour(key, in_text)
+    out_text = arcfour(key, cypher_text)
+    assert in_text == out_text, 'Failed arcfour_test'
+    return size
+
+
+def main(workers=None):
+    if workers:
+        workers = int(workers)
+    t0 = time.time()
+
+    with futures.ProcessPoolExecutor(workers) as executor:
+        actual_workers = executor._max_workers
+        to_do = []
+        for i in range(JOBS, 0, -1):
+            size = SIZE + int(SIZE / JOBS * (i - JOBS/2))
+            job = executor.submit(arcfour_test, size, KEY)
+            to_do.append(job)
+
+        for future in futures.as_completed(to_do):
+            res = future.result()
+            print('{:.1f} KB'.format(res/2**10))
+
+    print(STATUS.format(actual_workers, time.time() - t0))
+
+if __name__ == '__main__':
+    if len(sys.argv) == 2:
+        workers = int(sys.argv[1])
+    else:
+        workers = None
+    main(workers)

17-futures/crypto/arcfour_test.py

@@ -0,0 +1,119 @@
+#!/usr/bin/env python3
+
+from arcfour import arcfour
+
+'''
+Source of the test vectors:
+    A Stream Cipher Encryption Algorithm "Arcfour"
+    http://tools.ietf.org/html/draft-kaukonen-cipher-arcfour-03
+'''
+
+TEST_VECTORS = [
+    ('CRYPTLIB',    {
+        'Plain Text'  : (0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00),
+        'Key'         : (0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF),
+        'Cipher Text' : (0x74, 0x94, 0xC2, 0xE7, 0x10, 0x4B, 0x08, 0x79),
+        }
+    ),
+    ('COMMERCE',    {
+        'Plain Text'  : (0xdc, 0xee, 0x4c, 0xf9, 0x2c),
+        'Key'         : (0x61, 0x8a, 0x63, 0xd2, 0xfb),
+        'Cipher Text' : (0xf1, 0x38, 0x29, 0xc9, 0xde),
+        }
+    ),
+    ('SSH ARCFOUR', {
+        'Plain Text'  : (
+            0x52, 0x75, 0x69, 0x73, 0x6c, 0x69, 0x6e, 0x6e,
+            0x75, 0x6e, 0x20, 0x6c, 0x61, 0x75, 0x6c, 0x75,
+            0x20, 0x6b, 0x6f, 0x72, 0x76, 0x69, 0x73, 0x73,
+            0x73, 0x61, 0x6e, 0x69, 0x2c, 0x20, 0x74, 0xe4,
+            0x68, 0x6b, 0xe4, 0x70, 0xe4, 0x69, 0x64, 0x65,
+            0x6e, 0x20, 0x70, 0xe4, 0xe4, 0x6c, 0x6c, 0xe4,
+            0x20, 0x74, 0xe4, 0x79, 0x73, 0x69, 0x6b, 0x75,
+            0x75, 0x2e, 0x20, 0x4b, 0x65, 0x73, 0xe4, 0x79,
+            0xf6, 0x6e, 0x20, 0x6f, 0x6e, 0x20, 0x6f, 0x6e,
+            0x6e, 0x69, 0x20, 0x6f, 0x6d, 0x61, 0x6e, 0x61,
+            0x6e, 0x69, 0x2c, 0x20, 0x6b, 0x61, 0x73, 0x6b,
+            0x69, 0x73, 0x61, 0x76, 0x75, 0x75, 0x6e, 0x20,
+            0x6c, 0x61, 0x61, 0x6b, 0x73, 0x6f, 0x74, 0x20,
+            0x76, 0x65, 0x72, 0x68, 0x6f, 0x75, 0x75, 0x2e,
+            0x20, 0x45, 0x6e, 0x20, 0x6d, 0x61, 0x20, 0x69,
+            0x6c, 0x6f, 0x69, 0x74, 0x73, 0x65, 0x2c, 0x20,
+            0x73, 0x75, 0x72, 0x65, 0x20, 0x68, 0x75, 0x6f,
+            0x6b, 0x61, 0x61, 0x2c, 0x20, 0x6d, 0x75, 0x74,
+            0x74, 0x61, 0x20, 0x6d, 0x65, 0x74, 0x73, 0xe4,
+            0x6e, 0x20, 0x74, 0x75, 0x6d, 0x6d, 0x75, 0x75,
+            0x73, 0x20, 0x6d, 0x75, 0x6c, 0x6c, 0x65, 0x20,
+            0x74, 0x75, 0x6f, 0x6b, 0x61, 0x61, 0x2e, 0x20,
+            0x50, 0x75, 0x75, 0x6e, 0x74, 0x6f, 0x20, 0x70,
+            0x69, 0x6c, 0x76, 0x65, 0x6e, 0x2c, 0x20, 0x6d,
+            0x69, 0x20, 0x68, 0x75, 0x6b, 0x6b, 0x75, 0x75,
+            0x2c, 0x20, 0x73, 0x69, 0x69, 0x6e, 0x74, 0x6f,
+            0x20, 0x76, 0x61, 0x72, 0x61, 0x6e, 0x20, 0x74,
+            0x75, 0x75, 0x6c, 0x69, 0x73, 0x65, 0x6e, 0x2c,
+            0x20, 0x6d, 0x69, 0x20, 0x6e, 0x75, 0x6b, 0x6b,
+            0x75, 0x75, 0x2e, 0x20, 0x54, 0x75, 0x6f, 0x6b,
+            0x73, 0x75, 0x74, 0x20, 0x76, 0x61, 0x6e, 0x61,
+            0x6d, 0x6f, 0x6e, 0x20, 0x6a, 0x61, 0x20, 0x76,
+            0x61, 0x72, 0x6a, 0x6f, 0x74, 0x20, 0x76, 0x65,
+            0x65, 0x6e, 0x2c, 0x20, 0x6e, 0x69, 0x69, 0x73,
+            0x74, 0xe4, 0x20, 0x73, 0x79, 0x64, 0xe4, 0x6d,
+            0x65, 0x6e, 0x69, 0x20, 0x6c, 0x61, 0x75, 0x6c,
+            0x75, 0x6e, 0x20, 0x74, 0x65, 0x65, 0x6e, 0x2e,
+            0x20, 0x2d, 0x20, 0x45, 0x69, 0x6e, 0x6f, 0x20,
+            0x4c, 0x65, 0x69, 0x6e, 0x6f),
+        'Key'         : (
+            0x29, 0x04, 0x19, 0x72, 0xfb, 0x42, 0xba, 0x5f,
+            0xc7, 0x12, 0x77, 0x12, 0xf1, 0x38, 0x29, 0xc9),
+        'Cipher Text' : (
+            0x35, 0x81, 0x86, 0x99, 0x90, 0x01, 0xe6, 0xb5,
+            0xda, 0xf0, 0x5e, 0xce, 0xeb, 0x7e, 0xee, 0x21,
+            0xe0, 0x68, 0x9c, 0x1f, 0x00, 0xee, 0xa8, 0x1f,
+            0x7d, 0xd2, 0xca, 0xae, 0xe1, 0xd2, 0x76, 0x3e,
+            0x68, 0xaf, 0x0e, 0xad, 0x33, 0xd6, 0x6c, 0x26,
+            0x8b, 0xc9, 0x46, 0xc4, 0x84, 0xfb, 0xe9, 0x4c,
+            0x5f, 0x5e, 0x0b, 0x86, 0xa5, 0x92, 0x79, 0xe4,
+            0xf8, 0x24, 0xe7, 0xa6, 0x40, 0xbd, 0x22, 0x32,
+            0x10, 0xb0, 0xa6, 0x11, 0x60, 0xb7, 0xbc, 0xe9,
+            0x86, 0xea, 0x65, 0x68, 0x80, 0x03, 0x59, 0x6b,
+            0x63, 0x0a, 0x6b, 0x90, 0xf8, 0xe0, 0xca, 0xf6,
+            0x91, 0x2a, 0x98, 0xeb, 0x87, 0x21, 0x76, 0xe8,
+            0x3c, 0x20, 0x2c, 0xaa, 0x64, 0x16, 0x6d, 0x2c,
+            0xce, 0x57, 0xff, 0x1b, 0xca, 0x57, 0xb2, 0x13,
+            0xf0, 0xed, 0x1a, 0xa7, 0x2f, 0xb8, 0xea, 0x52,
+            0xb0, 0xbe, 0x01, 0xcd, 0x1e, 0x41, 0x28, 0x67,
+            0x72, 0x0b, 0x32, 0x6e, 0xb3, 0x89, 0xd0, 0x11,
+            0xbd, 0x70, 0xd8, 0xaf, 0x03, 0x5f, 0xb0, 0xd8,
+            0x58, 0x9d, 0xbc, 0xe3, 0xc6, 0x66, 0xf5, 0xea,
+            0x8d, 0x4c, 0x79, 0x54, 0xc5, 0x0c, 0x3f, 0x34,
+            0x0b, 0x04, 0x67, 0xf8, 0x1b, 0x42, 0x59, 0x61,
+            0xc1, 0x18, 0x43, 0x07, 0x4d, 0xf6, 0x20, 0xf2,
+            0x08, 0x40, 0x4b, 0x39, 0x4c, 0xf9, 0xd3, 0x7f,
+            0xf5, 0x4b, 0x5f, 0x1a, 0xd8, 0xf6, 0xea, 0x7d,
+            0xa3, 0xc5, 0x61, 0xdf, 0xa7, 0x28, 0x1f, 0x96,
+            0x44, 0x63, 0xd2, 0xcc, 0x35, 0xa4, 0xd1, 0xb0,
+            0x34, 0x90, 0xde, 0xc5, 0x1b, 0x07, 0x11, 0xfb,
+            0xd6, 0xf5, 0x5f, 0x79, 0x23, 0x4d, 0x5b, 0x7c,
+            0x76, 0x66, 0x22, 0xa6, 0x6d, 0xe9, 0x2b, 0xe9,
+            0x96, 0x46, 0x1d, 0x5e, 0x4d, 0xc8, 0x78, 0xef,
+            0x9b, 0xca, 0x03, 0x05, 0x21, 0xe8, 0x35, 0x1e,
+            0x4b, 0xae, 0xd2, 0xfd, 0x04, 0xf9, 0x46, 0x73,
+            0x68, 0xc4, 0xad, 0x6a, 0xc1, 0x86, 0xd0, 0x82,
+            0x45, 0xb2, 0x63, 0xa2, 0x66, 0x6d, 0x1f, 0x6c,
+            0x54, 0x20, 0xf1, 0x59, 0x9d, 0xfd, 0x9f, 0x43,
+            0x89, 0x21, 0xc2, 0xf5, 0xa4, 0x63, 0x93, 0x8c,
+            0xe0, 0x98, 0x22, 0x65, 0xee, 0xf7, 0x01, 0x79,
+            0xbc, 0x55, 0x3f, 0x33, 0x9e, 0xb1, 0xa4, 0xc1,
+            0xaf, 0x5f, 0x6a, 0x54, 0x7f),
+        }
+    ),
+]
+
+for name, vectors in TEST_VECTORS:
+    print(name, end='')
+    plain = bytearray(vectors['Plain Text'])
+    cipher = bytearray(vectors['Cipher Text'])
+    key = bytearray(vectors['Key'])
+    assert cipher == arcfour(key, plain, loops=1)
+    assert plain == arcfour(key, cipher, loops=1)
+    print(' --> OK')

17-futures/crypto/sha-timings.txt

@@ -0,0 +1,50 @@
+workers|time
+4|8.88
+3|11.14
+2|13.66
+1|22.80
+1|25.42
+2|16.37
+3|12.09
+4|11.06
+4|11.40
+3|11.51
+2|15.20
+1|24.18
+1|22.09
+2|12.48
+3|10.78
+4|10.48
+4|8.48
+3|10.07
+2|12.42
+1|20.24
+1|20.31
+2|11.39
+3|10.88
+4|10.44
+4|10.43
+3|11.11
+2|12.39
+1|20.69
+1|20.53
+2|11.80
+3|11.01
+4|10.52
+4|11.50
+3|14.45
+2|16.95
+1|24.77
+1|22.71
+2|18.35
+3|12.66
+4|12.20
+4|12.37
+3|13.37
+2|19.30
+1|24.30
+1|23.93
+2|18.51
+3|13.88
+4|12.97
+

17-futures/crypto/sha_futures.py

@@ -0,0 +1,38 @@
+import sys
+import time
+import hashlib
+from concurrent import futures
+from random import randrange
+
+JOBS = 12
+SIZE = 2**20
+STATUS = '{} workers, elapsed time: {:.2f}s'
+
+
+def sha(size):
+    data = bytearray(randrange(256) for i in range(size))
+    algo = hashlib.new('sha256')
+    algo.update(data)
+    return algo.hexdigest()
+
+
+def main(workers=None):
+    if workers:
+        workers = int(workers)
+    t0 = time.time()
+
+    with futures.ProcessPoolExecutor(workers) as executor:
+        actual_workers = executor._max_workers
+        to_do = (executor.submit(sha, SIZE) for i in range(JOBS))
+        for future in futures.as_completed(to_do):
+            res = future.result()
+            print(res)
+
+    print(STATUS.format(actual_workers, time.time() - t0))
+
+if __name__ == '__main__':
+    if len(sys.argv) == 2:
+        workers = int(sys.argv[1])
+    else:
+        workers = None
+    main(workers)

18-asyncio/spinner_asyncio.py

@@ -0,0 +1,53 @@
+# spinner_asyncio.py
+
+# credits: Example by Luciano Ramalho inspired by
+# Michele Simionato's multiprocessing example in the python-list:
+# https://mail.python.org/pipermail/python-list/2009-February/538048.html
+
+# BEGIN SPINNER_ASYNCIO
+import asyncio
+import itertools
+import sys
+
+
+@asyncio.coroutine
+def spin(msg):  # <1>
+    write, flush = sys.stdout.write, sys.stdout.flush
+    for char in itertools.cycle('|/-\\'):
+        status = char + ' ' + msg
+        write(status)
+        flush()
+        write('\x08' * len(status))
+        try:
+            yield from asyncio.sleep(.1)  # <2>
+        except asyncio.CancelledError:  # <3>
+            break
+    write(' ' * len(status) + '\x08' * len(status))
+
+
+@asyncio.coroutine
+def slow_computation():  # <4>
+    # fake computation waiting a long time for I/O
+    yield from asyncio.sleep(3)  # <5>
+    return 42
+
+
+@asyncio.coroutine
+def supervisor():  # <6>
+    spinner = asyncio.async(spin('thinking!'))  # <7>
+    print('spinner object:', spinner)  # <8>
+    result = yield from slow_computation()  # <9>
+    spinner.cancel()  # <10>
+    return result
+
+
+def main():
+    loop = asyncio.get_event_loop()  # <11>
+    result = loop.run_until_complete(supervisor())  # <12>
+    loop.close()
+    print('Answer:', result)
+
+
+if __name__ == '__main__':
+    main()
+# END SPINNER_ASYNCIO

18-asyncio/spinner_thread.py

@@ -0,0 +1,56 @@
+# spinner_thread.py
+
+# credits: Adapted from Michele Simionato's
+# multiprocessing example in the python-list:
+# https://mail.python.org/pipermail/python-list/2009-February/538048.html
+
+# BEGIN SPINNER_THREAD
+import threading
+import itertools
+import time
+import sys
+
+
+class Signal:  # <1>
+    go = True
+
+
+def spin(msg, signal):  # <2>
+    write, flush = sys.stdout.write, sys.stdout.flush
+    for char in itertools.cycle('|/-\\'):  # <3>
+        status = char + ' ' + msg
+        write(status)
+        flush()
+        write('\x08' * len(status))  # <4>
+        time.sleep(.1)
+        if not signal.go:  # <5>
+            break
+    write(' ' * len(status) + '\x08' * len(status))  # <6>
+
+
+def slow_computation():  # <7>
+    # fake computation waiting a long time for I/O
+    time.sleep(3)  # <8>
+    return 42
+
+
+def supervisor():  # <9>
+    signal = Signal()
+    spinner = threading.Thread(None, spin,
+                               args=('thinking!', signal))
+    print('spinner object:', spinner)  # <10>
+    spinner.start()  # <11>
+    result = slow_computation()  # <12>
+    signal.go = False  # <13>
+    spinner.join()  # <14>
+    return result
+
+
+def main():
+    result = supervisor()  # <15>
+    print('Answer:', result)
+
+
+if __name__ == '__main__':
+    main()
+# END SPINNER_THREAD

21-class-metaprog/evaldecos.py

@@ -0,0 +1,22 @@
+def deco_alpha(func):
+    print('<<100>> deco_alpha')
+
+    def inner_alpha():
+        print('<<200>> deco_alpha')
+        func()
+
+    return inner_alpha
+
+
+def deco_beta(cls):
+    print('<<300>> deco_beta')
+
+    def inner_beta(self):
+        print('<<400>> inner_beta')
+        print("result from 'deco_beta::inner_beta'")
+
+    cls.method3 = inner_beta
+    return cls
+
+
+print('<<500>> evaldecos mudule body')

21-class-metaprog/evaltime.py

@@ -0,0 +1,92 @@
+import atexit
+
+from evaldecos import deco_alpha
+from evaldecos import deco_beta
+
+
+print('<<1>> start')
+
+
+func_A = lambda: print('<<2>> func_A')
+
+
+def func_B():
+    print('<<3>> func_B')
+
+    def func_C():
+        print('<<4>> func_C')
+
+    return func_C
+
+
+@deco_alpha
+def func_D():
+    print('<<6>> func_D')
+
+
+def func_E():
+    print('<<7>> func_E')
+
+
+class ClassOne(object):
+    print('<<7>> ClassOne body')
+
+    def __init__(self):
+        print('<<8>> ClassOne.__init__')
+
+    def __del__(self):
+        print('<<9>> ClassOne.__del__')
+
+    def method1(self):
+        print('<<10>> ClassOne.method')
+        return "result from 'ClassOne.method1'"
+
+    class ClassTwo(object):
+        print('<<11>> ClassTwo body')
+
+
+@deco_beta
+class ClassThree(ClassOne):
+    print('<<12>> ClassThree body')
+
+    def method3(self):
+        print('<<13>> ClassOne.method')
+        return "result from 'ClassThree.method3'"
+
+
+if True:
+    print("<<14>> 'if True'")
+
+
+if False:
+    print("<<15>> 'if False'")
+
+
+atexit.register(func_E)
+
+print("<<16>> right before 'if ... __main__'")
+
+
+if __name__ == '__main__':
+    print('<<17>> start __main__ block')
+    print(func_A)
+    print(func_A())
+    print('<<18>> continue __main__ block')
+    print(func_B)
+    b_result = func_B()
+    print(b_result)
+    one = ClassOne()
+    one.method1()
+    b_result()
+    print(func_D)
+    func_D()
+    three = ClassThree()
+    three.method3()
+
+    class ClassFour(object):
+        print('<<19>> ClasFour body')
+
+    print('<<20>> end __main__ block')
+
+
+print('<<21>> The End')

21-class-metaprog/factories.py

@@ -0,0 +1,50 @@
+"""
+record_factory: create simple classes just for holding data fields
+
+# BEGIN RECORD_FACTORY_DEMO
+    >>> Dog = record_factory('Dog', 'name weight owner')  # <1>
+    >>> rex = Dog('Rex', 30, 'Bob')
+    >>> rex  # <2>
+    Dog(name='Rex', weight=30, owner='Bob')
+    >>> name, weight, _ = rex  # <3>
+    >>> name, weight
+    ('Rex', 30)
+    >>> "{2}'s dog weights {1}kg".format(*rex)
+    "Bob's dog weights 30kg"
+    >>> rex.weight = 32  # <4>
+    >>> rex
+    Dog(name='Rex', weight=32, owner='Bob')
+    >>> Dog.__mro__  # <5>
+    (<class 'factories.Dog'>, <class 'object'>)
+
+# END RECORD_FACTORY_DEMO
+"""
+
+# BEGIN RECORD_FACTORY
+def record_factory(cls_name, field_names):
+    if isinstance(field_names, str):  # <1>
+        field_names = field_names.replace(',', ' ').split()
+    __slots__ = tuple(field_names)
+
+    def __init__(self, *args, **kwargs):
+        attrs = dict(zip(self.__slots__, args))
+        attrs.update(kwargs)
+        for name, value in attrs.items():
+            setattr(self, name, value)
+
+    def __iter__(self):
+        for name in self.__slots__:
+            yield getattr(self, name)
+
+    def __repr__(self):
+        values = ', '.join('{}={!r}'.format(*i) for i
+                           in zip(self.__slots__, self))
+        return '{}({})'.format(self.__class__.__name__, values)
+
+    cls_attrs = dict(__slots__ = __slots__,
+                     __init__ = __init__,
+                     __iter__ = __iter__,
+                     __repr__ = __repr__)
+
+    return type(cls_name, (object,), cls_attrs)
+# END RECORD_FACTORY

concurrency/spinner_asyncio.py

@@ -0,0 +1,42 @@
+# spinner_asyncio.py
+
+# credits: Example by Luciano Ramalho inspired by
+# Michele Simionato's multiprocessing example
+# source:
+# http://python-3-patterns-idioms-test.readthedocs.org/en/latest/CoroutinesAndConcurrency.html
+
+import sys
+import asyncio
+
+DELAY = 0.1
+DISPLAY = '|/-\\'
+
+@asyncio.coroutine
+def spinner_func(before='', after=''):
+    write, flush = sys.stdout.write, sys.stdout.flush
+    while True:
+        for char in DISPLAY:
+            msg = '{} {} {}'.format(before, char, after)
+            write(msg)
+            flush()
+            write('\x08' * len(msg))
+            try:
+                yield from asyncio.sleep(DELAY)
+            except asyncio.CancelledError:
+                return
+
+
+@asyncio.coroutine
+def long_computation(delay):
+    # emulate a long computation
+    yield from asyncio.sleep(delay)
+
+
+if __name__ == '__main__':
+    loop = asyncio.get_event_loop()
+    spinner = loop.create_task(spinner_func('Please wait...', 'thinking!'))
+    long_task = loop.create_task(long_computation(3))
+    long_task.add_done_callback(lambda f: spinner.cancel())
+    loop.run_until_complete(spinner)
+    loop.close()
+

concurrency/spinner_asyncio2.py

@@ -0,0 +1,46 @@
+# spinner_asyncio2.py
+
+# credits: Example by Luciano Ramalho inspired by
+# Michele Simionato's multiprocessing example
+# source:
+# http://python-3-patterns-idioms-test.readthedocs.org/en/latest/CoroutinesAndConcurrency.html
+
+import sys
+import asyncio
+
+DELAY = 0.1
+DISPLAY = '|/-\\'
+
+@asyncio.coroutine
+def spinner_func(before='', after=''):
+    write, flush = sys.stdout.write, sys.stdout.flush
+    while True:
+        for char in DISPLAY:
+            msg = '{} {} {}'.format(before, char, after)
+            write(msg)
+            flush()
+            write('\x08' * len(msg))
+            try:
+                yield from asyncio.sleep(DELAY)
+            except asyncio.CancelledError:
+                return
+
+
+@asyncio.coroutine
+def long_computation(delay):
+    # emulate a long computation
+    yield from asyncio.sleep(delay)
+
+
+@asyncio.coroutine
+def supervisor(delay):
+    spinner = loop.create_task(spinner_func('Please wait...', 'thinking!'))
+    yield from long_computation(delay)
+    spinner.cancel()
+
+
+if __name__ == '__main__':
+    loop = asyncio.get_event_loop()
+    loop.run_until_complete(supervisor(3))
+    loop.close()
+

futures/charfinder/http_charfinder.py

@@ -39,8 +39,8 @@ def home(request):  # <1>
 
     html = template.format(query=query, result=res,  # <5>
                            message=msg)
-    print('Sending {} results'.format(len(descriptions)))
+    print('Sending {} results'.format(len(descriptions)))  # <6>
-    return web.Response(content_type=CONTENT_TYPE, text=html)
+    return web.Response(content_type=CONTENT_TYPE, text=html) # <7>
 # END HTTP_CHARFINDER_HOME
 
 

futures/countries/flags_processpool.py

@@ -0,0 +1,42 @@
+"""Download flags of top 20 countries by population
+
+ProcessPoolExecutor version
+
+Sample run::
+
+    $ python3 flags_threadpool.py
+    BD retrieved.
+    EG retrieved.
+    CN retrieved.
+    ...
+    PH retrieved.
+    US retrieved.
+    IR retrieved.
+    20 flags downloaded in 0.93s
+
+"""
+# BEGIN FLAGS_PROCESSPOOL
+from concurrent import futures
+
+from flags import save_flag, get_flag, show, main
+
+MAX_WORKERS = 20
+
+
+def download_one(cc):
+    image = get_flag(cc)
+    show(cc)
+    save_flag(image, cc.lower() + '.gif')
+    return cc
+
+
+def download_many(cc_list):
+    with futures.ProcessPoolExecutor() as executor:  # <1>
+        res = executor.map(download_one, sorted(cc_list))
+
+    return len(list(res))
+
+
+if __name__ == '__main__':
+    main(download_many)
+# END FLAGS_PROCESSPOOL

metaprog/plainpoint.py

@@ -0,0 +1,25 @@
+"""
+A class equivalent to the class statement below would be generated by this code:
+
+    >>> import collections
+    >>> Point = collections.plainclass('Point', 'x y')
+"""
+
+class Point(object):
+    __slots__ = ['x', 'y']  # save memory in the likely event there are many instances
+
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+
+    def __repr__(self):
+        return 'Point({!r}, {!r})'.format(self.x, self.y)
+
+    def __eq__(self, other):
+        if not isinstance(other, Point):
+            return NotImplemented
+        return self.x == other.x and self.y == other.y
+
+    def __iter__(self, other):  # support unpacking
+        yield self.x
+        yield self.y