Second edition, first upload

.gitignore

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+__pycache__/
+*.pyc

1st_edition/README.md

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+Introducing Python
+=================
+
+This repository contains the programs featured in _Introducing Python_.
+Some examples have been updated for the second and third printings.
+
+|directory|chapter|
+|---|---|
+|[intro](intro)|  1. A taste of Py
+|     |  2. Py ingredients: numbers, strings, and variables
+|     |  3. Py filling: lists, tuples, dictionaries, and sets
+|     |  4. Py crust: code structures
+|[boxes](boxes)|  5. Py boxes: modules, packages, and programs
+|     |  6. Oh oh: objects and classes
+|     |  7. Mangle data like a pro
+|[storage](storage)|8. Data has to go somewhere
+|[web](web)  |  9. The web, untangled
+|[sys](sys)  | 10. Systems
+|[net](net)  | 11. Concurrency and networks
+|[dev](dev)  | 12. Be a pythonista
+|[art](art)  |  A. Py art
+|[bus](bus)  |  B. Py at work
+|     |  C. Py sci
+|     |  D. Install Python 3
+|     |  E. Answers to exercises
+|     |  F. Cheatsheets

README.md

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-Introducing Python
+Introducing Python -- Second Edition
 =================
 
-This repository contains the programs featured in _Introducing Python_.
-Some examples have been updated for the second and third printings.
-
-|directory|chapter|
-|---|---|
-|[intro](intro)|  1. A taste of Py
-|     |  2. Py ingredients: numbers, strings, and variables
-|     |  3. Py filling: lists, tuples, dictionaries, and sets
-|     |  4. Py crust: code structures
-|[boxes](boxes)|  5. Py boxes: modules, packages, and programs
-|     |  6. Oh oh: objects and classes
-|     |  7. Mangle data like a pro
-|[storage](storage)|8. Data has to go somewhere
-|[web](web)  |  9. The web, untangled
-|[sys](sys)  | 10. Systems
-|[net](net)  | 11. Concurrency and networks
-|[dev](dev)  | 12. Be a pythonista
-|[art](art)  |  A. Py art
-|[bus](bus)  |  B. Py at work
-|     |  C. Py sci
-|     |  D. Install Python 3
-|     |  E. Answers to exercises
-|     |  F. Cheatsheets
+This repository contains the programs featured in 
+the second edition of the book _Introducing Python_.

ch01/archive.py

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+import webbrowser
+import json
+from urllib.request import urlopen
+
+print("Let's find an old website.")
+site = input("Type a website URL: ")
+era = input("Type a year, month, and day, like 20150613: ")
+url = "http://archive.org/wayback/available?url=%s&timestamp=%s" % (site, era)
+response = urlopen(url)
+contents = response.read()
+text = contents.decode("utf-8")
+data = json.loads(text)
+try:
+    old_site = data["archived_snapshots"]["closest"]["url"]
+    print("Found this copy: ", old_site)
+    print("It should appear in your browser now.")
+    webbrowser.open(old_site)
+except:
+    print("Sorry, no luck finding", site)

ch01/archive2.py

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+import webbrowser
+import requests
+
+print("Let's find an old website.")
+site = input("Type a website URL: ")
+era = input("Type a year, month, and day, like 20150613: ")
+url = "http://archive.org/wayback/available?url=%s&timestamp=%s" % (site, era)
+response = requests.get(url)
+data = response.json()
+try:
+    old_site = data["archived_snapshots"]["closest"]["url"]
+    print("Found this copy: ", old_site)
+    print("It should appear in your browser now.")
+    webbrowser.open(old_site)
+except:
+    print("Sorry, no luck finding", site)

ch01/countdown.py

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+for countdown in 5, 4, 3, 2, 1, "hey!":
+    print(countdown)

ch01/quotes.py

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+quotes = {
+    "Moe": "A wise guy, huh?",
+    "Larry": "Ow!",
+    "Curly": "Nyuk nyuk!",
+    }
+stooge = "Curly"
+print(stooge, "says:", quotes[stooge])

ch01/spells.py

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+spells = [
+    "Riddikulus!",
+    "Wingardium Leviosa!",
+    "Avada Kedavra!",
+    "Expecto Patronum!",
+    "Nox!",
+    "Lumos!",
+    ]
+print(spells[3])

ch05/poem.py

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+poem = '''There was a Young Lady of Norway,
+Who casually sat in a doorway;
+When the door squeezed her flat,
+She exclaimed, "What of that?"
+This courageous Young Lady of Norway.'''

ch05/poem2.py

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+poem2 = '''I do not like thee, Doctor Fell.
+    The reason why, I cannot tell.
+    But this I know, and know full well:
+    I do not like thee, Doctor Fell.
+'''

ch05/poem3.py

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+poem = '''All that doth flow we cannot liquid name
+Or else would fire and water be the same;
+But that is liquid which is moist and wet
+Fire that property can never get.
+Then 'tis not cold that doth the fire put out
+But 'tis the wet that makes it die, no doubt.'''

ch11/choices/advice.oy

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+from random import choice
+
+answers = ["Yes!", "No!", "Reply hazy", "Sorry, what?"]
+
+def give():
+    """Return random advice"""
+    return choice(answers)

ch11/choices/fast.py

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+from random import choice
+
+places = ["McDonalds", "KFC", "Burger King", "Taco Bell",
+          "Wendys", "Arbys", "Pizza Hut"]
+
+def pick():
+    """Return random fast food place"""
+    return choice(places)

ch11/fast.py

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+from random import choice
+
+places = ["McDonalds", "KFC", "Burger King", "Taco Bell",
+          "Wendys", "Arbys", "Pizza Hut"]
+
+def pick(): # see the docstring below?
+    """Return random fast food place"""
+    return choice(places)

ch11/fast2.py

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+places = ["McDonalds", "KFC", "Burger King", "Taco Bell",
+          "Wendys", "Arbys", "Pizza Hut"]
+
+def pick():
+    import random
+    return random.choice(places)

ch11/fast3.py

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+import fast as f
+
+place = f.pick()
+print("Let's go to", place)

ch11/fast4.py

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+from fast import pick
+
+place = pick()
+print("Let's go to", place)

ch11/fast5.py

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+from fast import pick as who_cares
+
+place = who_cares()
+print("Let's go to", place)

ch11/lunch.py

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+import fast
+
+place = fast.pick()
+print("Let's go to", place)

ch11/questions.py

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+from fast import pick as who_cares
+
+place = who_cares()
+print("Let's go to", place)

ch12/mammoth.txt

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+We have seen thee, queen of cheese,
+Lying quietly at your ease,
+Gently fanned by evening breeze,
+Thy fair form no flies dare seize.
+All gaily dressed soon you'll go
+To the great Provincial show,
+To be admired by many a beau
+In the city of Toronto.
+Cows numerous as a swarm of bees,
+Or as the leaves upon the trees,
+It did require to make thee please,
+And stand unrivalled, queen of cheese.
+May you not receive a scar as
+We have heard that Mr. Harris
+Intends to send you off as far as
+The great world's show at Paris.
+Of the youth beware of these,
+For some of them might rudely squeeze
+And bite your cheek, then songs or glees
+We could not sing, oh! queen of cheese.
+We'rt thou suspended from balloon,
+You'd cast a shade even at noon,
+Folks would think it was the moon
+About to fall and crush them soon.

ch14/convert_image.py

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+from io import BytesIO
+from PIL import Image
+import sys
+
+def data_to_img(data):
+    """Return PIL Image object, with data from in-memory <data>"""
+    fp = BytesIO(data)
+    return Image.open(fp) # reads from memory
+
+def img_to_data(img, fmt=None):
+    """Return image data from PIL Image <img>, in <fmt> format"""
+    fp = BytesIO()
+    if not fmt:
+        fmt = img.format # keeps the original format
+    img.save(fp, fmt) # writes to memory
+    return fp.getvalue()
+
+def convert_image(data, fmt=None):
+    """Convert image <data> to PIL <fmt> image data"""
+    img = data_to_img(data)
+    return img_to_data(img, fmt)
+
+def get_file_data(name):
+    """Return PIL Image object for image file <name>"""
+    img = Image.open(name)
+    print("img", img, img.format)
+    return img_to_data(img)
+
+if __name__ == "__main__":
+    for name in sys.argv[1:]:
+        data = get_file_data(name)
+        print("in", len(data), data[:10])
+        for fmt in ("gif", "png", "jpeg"):
+            out_data = convert_image(data, fmt)
+            print("out", len(out_data), out_data[:10])

ch15/cf.py

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+from concurrent import futures
+import math
+import time
+import sys
+
+def calc(val):
+    time.sleep(1)
+    result = math.sqrt(float(val))
+    return result
+
+def use_threads(num, values):
+    t1 = time.time()
+    with futures.ThreadPoolExecutor(num) as tex:
+        results = tex.map(calc, values)
+    t2 = time.time()
+    return t2 - t1
+
+def use_processes(num, values):
+    t1 = time.time()
+    with futures.ProcessPoolExecutor(num) as pex:
+        results = pex.map(calc, values)
+    t2 = time.time()
+    return t2 - t1
+
+def main(workers, values):
+    print(f"Using {workers} workers for {len(values)} values")
+    t_sec = use_threads(workers, values)
+    print(f"Threads took {t_sec:.4f} seconds")
+    p_sec = use_processes(workers, values)
+    print(f"Processes took {p_sec:.4f} seconds")
+
+if __name__ == '__main__':
+    workers = int(sys.argv[1])
+    values = list(range(1, 6)) # 1 .. 5
+    main(workers, values)

ch15/cf2.py

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+from concurrent import futures
+import math
+import sys
+
+def calc(val):
+    result = math.sqrt(float(val))
+    return val, result
+
+def use_threads(num, values):
+    with futures.ThreadPoolExecutor(num) as tex:
+        tasks = [tex.submit(calc, value) for value in values]
+        for f in futures.as_completed(tasks):
+            yield f.result()
+
+def use_processes(num, values):
+    with futures.ProcessPoolExecutor(num) as pex:
+        tasks = [pex.submit(calc, value) for value in values]
+        for f in futures.as_completed(tasks):
+            yield f.result()
+
+def main(workers, values):
+    print(f"Using {workers} workers for {len(values)} values")
+    print("Using threads:")
+    for val, result in use_threads(workers, values):
+        print(f'{val} {result:.4f}')
+    print("Using processes:")
+    for val, result in use_processes(workers, values):
+        print(f'{val} {result:.4f}')
+
+if __name__ == '__main__':
+    workers = 3
+    if len(sys.argv) > 1:
+        workers = int(sys.argv[1])
+    values = list(range(1, 6)) # 1 .. 5
+    main(workers, values)

ch15/dishes.py

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+import multiprocessing as mp
+
+def washer(dishes, output):
+    for dish in dishes:
+        print('Washing', dish, 'dish')
+        output.put(dish)
+
+def dryer(input):
+    while True:
+        dish = input.get()
+        print('Drying', dish, 'dish')
+        input.task_done()
+
+dish_queue = mp.JoinableQueue()
+dryer_proc = mp.Process(target=dryer, args=(dish_queue,))
+dryer_proc.daemon = True
+dryer_proc.start()
+dishes = ['salad', 'bread', 'entree', 'dessert']
+washer(dishes, dish_queue)
+dish_queue.join()

ch15/gevent_monkey.py

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+import gevent
+from gevent import monkey; monkey.patch_all()
+import socket
+
+hosts = ['www.crappytaxidermy.com', 'www.walterpottertaxidermy.com',
+         'www.antique-taxidermy.com']
+jobs = [gevent.spawn(socket.gethostbyname, host) for host in hosts]
+gevent.joinall(jobs, timeout=5)
+for job in jobs:
+    print(job.value)

ch15/gevent_test.py

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+import gevent
+from gevent import socket
+
+hosts = ['www.crappytaxidermy.com', 'www.walterpottertaxidermy.com',
+         'www.antique-taxidermy.com']
+jobs = [gevent.spawn(gevent.socket.gethostbyname, host) for host in hosts]
+gevent.joinall(jobs, timeout=5)
+for job in jobs:
+    print(job.value)

ch15/knock_client.py

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+from twisted.internet import reactor, protocol
+
+class KnockClient(protocol.Protocol):
+
+    def connectionMade(self):
+        self.transport.write("Knock knock")
+
+    def dataReceived(self, data):
+        if data.startswith("Who's there?"):
+            response = "Disappearing client"
+            self.transport.write(response)
+        else:
+            self.transport.loseConnection()
+            reactor.stop()
+
+class KnockFactory(protocol.ClientFactory):
+    protocol = KnockClient
+
+def main():
+    f = KnockFactory()
+    reactor.connectTCP("localhost", 8000, f)
+    reactor.run()
+
+if __name__ == '__main__':
+    main()