added code examples for chapters 13-17

Author: Mike Driscoll

chapter12_unicode/README.txt

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+The examples in chapter 12 don't translate into good examples and can be easily
+copied and pasted from the book into your interpreter.

chapter13_benchmarking/memo_prof.py

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+# memo_prof.py
+@profile
+def mem_func():
+    lots_of_numbers = list(range(1500))
+    x = ['letters'] * (5 ** 10)
+    del lots_of_numbers
+    return None
+
+if __name__ == '__main__':
+    mem_func()

chapter13_benchmarking/profhooks.py

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+# profhooks.py
+from profilehooks import profile
+
+
+@profile
+def mem_func():
+    lots_of_numbers = list(range(1500))
+    x = ['letters'] * (5 ** 10)
+    del lots_of_numbers
+    return None
+
+if __name__ == '__main__':
+    mem_func()

chapter13_benchmarking/profhooks2.py

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+# profhooks2.py
+from profilehooks import timecall
+
+@timecall
+def mem_func():
+    lots_of_numbers = list(range(1500))
+    x = ['letters'] * (5 ** 10)
+    del lots_of_numbers
+    return None
+
+if __name__ == '__main__':
+    mem_func()

chapter13_benchmarking/silly_functions.py

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+# silly_functions.py
+import time
+
+@profile
+def fast_function():
+    print("I'm a fast function!")
+
+@profile
+def slow_function():
+    time.sleep(2)
+    print("I'm a slow function")
+
+if __name__ == '__main__':
+    fast_function()
+    slow_function()

chapter13_benchmarking/simple_func.py

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+# simple_func.py
+def my_function():
+    try:
+        1 / 0
+    except ZeroDivisionError:
+        pass

chapter13_benchmarking/simple_func2.py

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+def my_function():
+    try:
+        1 / 0
+    except ZeroDivisionError:
+        pass
+
+if __name__ == "__main__":
+    import timeit
+    setup = "from __main__ import my_function"
+    print(timeit.timeit("my_function()", setup=setup))

chapter13_benchmarking/timing_context_manager.py

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+import random
+import time
+
+class MyTimer():
+
+    def __init__(self):
+        self.start = time.time()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        end = time.time()
+        runtime = end - self.start
+        msg = 'The function took {time} seconds to complete'
+        print(msg.format(time=runtime))
+
+
+def long_runner():
+    for x in range(5):
+        sleep_time = random.choice(range(1,5))
+        time.sleep(sleep_time)
+
+
+if __name__ == '__main__':
+    with MyTimer():
+        long_runner()

chapter13_benchmarking/timing_decorator.py

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+import random
+import time
+
+def timerfunc(func):
+    """
+    A timer decorator
+    """
+    def function_timer(*args, **kwargs):
+        """
+        A nested function for timing other functions
+        """
+        start = time.time()
+        value = func(*args, **kwargs)
+        end = time.time()
+        runtime = end - start
+        msg = "The runtime for {func} took {time} seconds to complete"
+        print(msg.format(func=func.__name__,
+                         time=runtime))
+        return value
+    return function_timer
+
+
+@timerfunc
+def long_runner():
+    for x in range(5):
+        sleep_time = random.choice(range(1,5))
+        time.sleep(sleep_time)
+
+if __name__ == '__main__':
+    long_runner()

chapter14_encryption/fernet_encryption.py

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+from cryptography.fernet import Fernet
+
+cipher_key = Fernet.generate_key()
+print(cipher_key)
+
+cipher = Fernet(cipher_key)
+text = b'My super secret message'
+encrypted_text = cipher.encrypt(text)
+print(encrypted_text)
+
+decrypted_text = cipher.decrypt(encrypted_text)
+print(decrypted_text)