updated from Atlas

attic/decorators/average_broken.py

@@ -0,0 +1,20 @@
+"""
+>>> avg = make_averager()
+>>> avg(10)
+Traceback (most recent call last):
+  ...
+UnboundLocalError: local variable 'num_items' referenced before assignment
+
+"""
+
+
+def make_averager():
+    num_items = 0
+    total = 0
+
+    def averager(new_value):
+        num_items += 1
+        total += new_value
+        return total / num_items
+
+    return averager

attic/decorators/average_fixed.py

@@ -0,0 +1,45 @@
+"""
+>>> avg = make_averager()
+>>> other_avg = make_averager()
+>>> avg(10)
+10.0
+>>> avg(11)
+10.5
+>>> avg(12)
+11.0
+>>> avg.__code__.co_varnames
+('new_value',)
+>>> avg.__code__.co_freevars
+('num_items', 'total')
+>>> avg.__closure__  # doctest: +ELLIPSIS
+(<cell at 0x...: int object at 0x...>, <cell at 0x...: int object at 0x...>)
+>>> avg.__closure__[0].cell_contents
+3
+>>> avg.__closure__[1].cell_contents
+33
+>>> other_avg(5)
+5.0
+>>> other_avg(10)
+7.5
+>>> other_avg(15)
+10.0
+"""
+
+DEMO = """
+>>> avg.__closure__
+(<cell at 0x10fd24f78: int object at 0x10f6d3db0>,
+ <cell at 0x10fd24d38: int object at 0x10f6d4170>)
+"""
+
+
+def make_averager():
+    num_items = 0
+    total = 0
+
+    def averager(new_value):
+        nonlocal num_items, total
+        num_items += 1
+        total += new_value
+        return total / num_items
+
+    return averager

attic/decorators/average_fixed_py2.py

@@ -0,0 +1,39 @@
+"""
+>>> avg = make_averager()
+>>> avg(10)
+10.0
+>>> avg(11)
+10.5
+>>> avg(12)
+11.0
+>>> avg.__code__.co_varnames
+('new_value',)
+>>> avg.__code__.co_freevars
+('ns',)
+>>> avg.__closure__  # doctest: +ELLIPSIS
+(<cell at 0x...: Namespace object at 0x...>,)
+>>> avg.__closure__[0].cell_contents.__dict__
+{'total': 33, 'num_items': 3}
+"""
+
+DEMO = """
+>>> avg.__closure__
+(<cell at 0x108df5980: Namespace object at 0x108e06790>,)
+"""
+
+
+class Namespace(object):
+    pass
+
+
+def make_averager():
+    ns = Namespace()
+    ns.num_items = 0
+    ns.total = 0
+
+    def averager(new_value):
+        ns.num_items += 1
+        ns.total += new_value
+        return float(ns.total) / ns.num_items
+
+    return averager

attic/decorators/average_partial.py

@@ -0,0 +1,34 @@
+"""
+>>> import functools
+>>> avg = functools.partial(averager, series=[])
+>>> avg(10)
+10.0
+>>> avg(11)
+10.5
+>>> avg(12)
+11.0
+>>> avg.args
+()
+>>> avg.keywords
+{'series': [10, 11, 12]}
+>>> avg.func            # doctest: +ELLIPSIS
+<function averager at 0x...>
+>>> avg.func.__code__.co_varnames
+('new_value', 'series', 'total')
+"""
+
+DEMO = """
+>>> avg.func
+<function averager at 0x1010c5560>
+>>> avg.func.__code__.co_varnames
+('new_value',)
+>>> avg.__code__.co_freevars
+('num_items', 'total')
+>>> avg.__closure__
+"""
+
+def averager(new_value, series):
+    series.append(new_value)
+    total = sum(series)
+    return float(total)/len(series)
+

attic/decorators/average_py2.py

@@ -0,0 +1,28 @@
+"""
+>>> avg = make_averager()
+>>> avg(10)
+10.0
+>>> avg(11)
+10.5
+>>> avg(12)
+11.0
+>>> avg.__code__.co_varnames
+('new_value', 'total')
+>>> avg.__code__.co_freevars
+('series',)
+>>> avg.__closure__  # doctest: +ELLIPSIS
+(<cell at 0x...: list object at 0x...>,)
+>>> avg.__closure__[0].cell_contents
+[10, 11, 12]
+"""
+
+
+def make_averager():
+    series = []
+
+    def averager(new_value):
+        series.append(new_value)
+        total = sum(series)
+        return float(total)/len(series)
+
+    return averager

attic/decorators/clockdeco.py

@@ -0,0 +1,15 @@
+# clockdeco.py
+
+import time
+
+
+def clock(func):
+    def clocked(*args):
+        t0 = time.time()
+        result = func(*args)
+        elapsed = time.time() - t0
+        name = func.__name__
+        arg_str = ', '.join(repr(arg) for arg in args)
+        print('[%0.8fs] %s(%s) -> %r' % (elapsed, name, arg_str, result))
+        return result
+    return clocked

attic/decorators/clockdeco2.py

@@ -0,0 +1,23 @@
+# clockdeco2.py
+
+import time
+import functools
+
+
+def clock(func):
+    @functools.wraps(func)
+    def clocked(*args, **kwargs):
+        t0 = time.time()
+        result = func(*args, **kwargs)
+        elapsed = time.time() - t0
+        name = func.__name__
+        arg_lst = []
+        if args:
+            arg_lst.append(', '.join(repr(arg) for arg in args))
+        if kwargs:
+            pairs = ['%s=%r' % (k, w) for k, w in sorted(kwargs.items())]
+            arg_lst.append(', '.join(pairs))
+        arg_str = ', '.join(arg_lst)
+        print('[%0.8fs] %s(%s) -> %r ' % (elapsed, name, arg_str, result))
+        return result
+    return clocked

attic/decorators/clockdeco2_demo.py

@@ -0,0 +1,31 @@
+# clockdec2o_demo.py
+
+"""
+>>> pythagoras(3, 4)        # doctest: +ELLIPSIS
+[0.0...s] pythagoras(3, 4) -> 5.0
+5.0
+>>> pythagoras(9, h=15)     # doctest: +ELLIPSIS
+[0.0...s] pythagoras(9, h=15) -> 12.0
+12.0
+
+"""
+import time
+import math
+from clockdeco2 import clock
+
+
+@clock
+def pythagoras(a, b=None, h=None):
+    if b is None and h is None:
+        raise TypeError('must provide second leg (b) or hypotenuse (h)')
+    if h is None:
+        return math.sqrt(a*a + b*b)
+    else:
+        return math.sqrt(h*h - a*a)
+
+
+if __name__=='__main__':
+    print('*' * 40, 'Calling pythagoras(3, 4)')
+    pythagoras(3, 4)
+    print('*' * 40, 'Calling pythagoras(9, h=15)')
+    pythagoras(9, h=15)

attic/decorators/clockdeco2_tests.py

@@ -0,0 +1,95 @@
+"""
+>>> f_empty()
+[0.0...s] f_empty() -> None
+>>> f_args('spam', 3)
+[0.0...s] f_args('spam', 3) -> 'spamspamspam'
+'spamspamspam'
+>>> snooze(1234)
+[1...s] snooze(1234) -> None
+>>> average(1, 2, 3)
+[0.0...s] average(1, 2, 3) -> 2.0
+2.0
+>>> average(*range(10**3))
+[0.0...s] average(0, 1, ..., 999) -> 499.5
+499.5
+>>> factorial(10)
+[0.000...s] factorial(1) -> 1
+[0.000...s] factorial(2) -> 2
+[0.000...s] factorial(3) -> 6
+[0.000...s] factorial(4) -> 24
+[0.000...s] factorial(5) -> 120
+[0.000...s] factorial(6) -> 720
+[0.000...s] factorial(7) -> 5040
+[0.000...s] factorial(8) -> 40320
+[0.000...s] factorial(9) -> 362880
+[0.000...s] factorial(10) -> 3628800
+3628800
+>>> fibonacci(1)
+[0.000...s] fibonacci(1) -> 1
+1
+>>> fibonacci(5)
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(0) -> 0
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(2) -> 1
+[0.000...s] fibonacci(3) -> 2
+[0.000...s] fibonacci(0) -> 0
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(2) -> 1
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(0) -> 0
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(2) -> 1
+[0.000...s] fibonacci(3) -> 2
+[0.000...s] fibonacci(4) -> 3
+[0.000...s] fibonacci(5) -> 5
+5
+>>> f_kwargs(3, 5, d='spam', c='eggs')
+[0.0...s] f_kwargs(3, 5, c='eggs', d='spam') -> 15
+15
+>>> f_args.__name__
+'f_args'
+>>> f_kwargs.__name__
+'f_kwargs'
+"""
+
+import time
+
+from clockdeco2 import clock
+
+@clock
+def f_empty():
+    pass
+
+@clock
+def f_args(a, b):
+    return a*b
+
+@clock
+def snooze(milis):
+    time.sleep(milis/1000)
+
+@clock
+def average(*args):
+    return sum(args) / len(args)
+
+@clock
+def factorial(n):
+    return 1 if n < 2 else n*factorial(n-1)
+
+@clock
+def fibonacci(n):
+    if n < 2:
+        return n
+    return fibonacci(n-2) + fibonacci(n-1)
+
+@clock
+def f_kwargs(a, b, c=1, d='eggs'):
+    from time import sleep
+    sleep(0.001)
+    return a*b
+
+
+
+import doctest
+doctest.testmod(optionflags=doctest.ELLIPSIS | doctest.NORMALIZE_WHITESPACE)

attic/decorators/clockdeco_demo2.py

@@ -0,0 +1,22 @@
+from clockdeco import clock
+
+import time
+
+@clock
+def snooze(milis):
+    time.sleep(milis/1000)
+
+@clock
+def factorial(n):
+    return 1 if n < 2 else n*factorial(n-1)
+
+
+@clock
+def fibonacci(n):
+    if n < 2:
+        return n
+    return fibonacci(n-2) + fibonacci(n-1)
+
+snooze(123)
+print(factorial(6))
+print(fibonacci(4))

attic/decorators/clockdeco_demo3.py

@@ -0,0 +1,20 @@
+import functools
+from clockdeco import clock
+
+
+@functools.lru_cache()
+@clock
+def factorial(n):
+    return 1 if n < 2 else n*factorial(n-1)
+
+
+@functools.lru_cache()
+@clock
+def fibonacci(n):
+    if n < 2:
+        return n
+    return fibonacci(n-2) + fibonacci(n-1)
+
+
+print(factorial(6))
+print(fibonacci(6))

attic/decorators/clockdeco_tests.py

@@ -0,0 +1,82 @@
+"""
+>>> f_empty()
+[0.0...s] f_empty() -> None
+>>> f_args('spam', 3)
+[0.0...s] f_args('spam', 3) -> 'spamspamspam'
+'spamspamspam'
+>>> snooze(1234)
+[1...s] snooze(1234) -> None
+>>> average(1, 2, 3)
+[0.0...s] average(1, 2, 3) -> 2.0
+2.0
+>>> average(*range(10**3))
+[0.0...s] average(0, 1, ..., 999) -> 499.5
+499.5
+>>> factorial(10)
+[0.000...s] factorial(1) -> 1
+[0.000...s] factorial(2) -> 2
+[0.000...s] factorial(3) -> 6
+[0.000...s] factorial(4) -> 24
+[0.000...s] factorial(5) -> 120
+[0.000...s] factorial(6) -> 720
+[0.000...s] factorial(7) -> 5040
+[0.000...s] factorial(8) -> 40320
+[0.000...s] factorial(9) -> 362880
+[0.000...s] factorial(10) -> 3628800
+3628800
+>>> fibonacci(1)
+[0.000...s] fibonacci(1) -> 1
+1
+>>> fibonacci(5)
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(0) -> 0
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(2) -> 1
+[0.000...s] fibonacci(3) -> 2
+[0.000...s] fibonacci(0) -> 0
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(2) -> 1
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(0) -> 0
+[0.000...s] fibonacci(1) -> 1
+[0.000...s] fibonacci(2) -> 1
+[0.000...s] fibonacci(3) -> 2
+[0.000...s] fibonacci(4) -> 3
+[0.000...s] fibonacci(5) -> 5
+5
+>>> f_args.__name__
+'clocked'
+"""
+
+import time
+
+from clockdeco import clock
+
+@clock
+def f_empty():
+    pass
+
+@clock
+def f_args(a, b):
+    return a*b
+
+@clock
+def snooze(milis):
+    time.sleep(milis/1000)
+
+@clock
+def average(*args):
+    return sum(args) / len(args)
+
+@clock
+def factorial(n):
+    return 1 if n < 2 else n*factorial(n-1)
+
+@clock
+def fibonacci(n):
+    if n < 2:
+        return n
+    return fibonacci(n-2) + fibonacci(n-1)
+
+import doctest
+doctest.testmod(optionflags=doctest.ELLIPSIS | doctest.NORMALIZE_WHITESPACE)

attic/decorators/currency.py

@@ -0,0 +1,50 @@
+# currency.py
+
+"""
+>>> convert(1, 'BRL', 'USD')
+0.4591
+>>> convert(1, 'USD', 'BRL')
+2.1784
+>>> convert(1, 'EUR', 'USD')
+1.3482
+>>> convert(1, 'USD', 'EUR')
+0.7417
+>>> convert(1, 'EUR', 'BRL')
+2.9369
+>>> convert(1, 'BRL', 'EUR')
+0.3405
+
+>>> from functools import partial
+>>> eur = partial(convert, cur_to='EUR')
+>>> eur(1, 'USD')
+0.7417
+>>> eur(1, 'BRL')
+0.3405
+>>> eur2brl = partial(convert, cur_from='EUR', cur_to='BRL')
+>>> eur2brl(100)
+293.6864
+>>> type(eur2brl)
+<class 'functools.partial'>
+"""
+
+DEMO = """
+>>> eur2brl.func
+<function convert at 0x1010c5560>
+>>> eur2brl.args, eur2brl.keywords
+((), {'cur_from': 'EUR', 'cur_to': 'BRL'})
+"""
+
+rates = {'BRL': 2.17836,
+         'CAD': 1.03615,
+         'CNY': 6.10562,
+         'EUR': 0.74173,
+         'GBP': 0.62814,
+         'INR': 61.8685,
+         'JPY': 98.6002,
+         'USD': 1.0}
+
+reference = rates['USD']
+
+def convert(amount, cur_from, cur_to):
+    ref_amount = reference / rates[cur_from] * amount
+    return round(ref_amount * rates[cur_to], 4)

attic/decorators/fibonacci.py

@@ -0,0 +1,60 @@
+
+# source: http://oeis.org/A000045
+fibo_seq = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610,
+            987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025,
+            121393, 196418, 317811, 514229, 832040, 1346269, 2178309,
+            3524578, 5702887, 9227465, 14930352, 24157817, 39088169]
+
+from functools import lru_cache
+
+def fibonacci(n):
+    if n < 2:
+        return n
+    return fibonacci(n-2) + fibonacci(n-1)
+
+@lru_cache()
+def fibonacci2(n):
+    if n < 2:
+        return n
+    return fibonacci2(n-2) + fibonacci2(n-1)
+
+def memoize(func):
+    '''simplest memoizing decorator'''
+    cache = {}
+    def memoized(*args):
+        if args not in cache:
+            cache[args] = func(*args)
+        return cache[args]
+    return memoized
+
+def test():
+    for i, expected in enumerate(fibo_seq[:31]):
+        print(i, expected)
+        assert fibonacci(i) == expected
+
+def chronograph():
+    global fibonacci
+    from time import time
+    t0 = time()
+    n = 32
+    res = fibonacci(n)
+    #res = [fibonacci(n) for n in range(30)]
+    t1 = time()
+    print(n, res, format(t1-t0, '0.6f'))
+
+    t0 = time()
+    res = fibonacci2(n)
+    #res = [fibonacci2(n) for n in range(30)]
+    t1 = time()
+    print(n, res, format(t1-t0, '0.6f'))
+
+    t0 = time()
+    fibonacci = memoize(fibonacci)
+    res = fibonacci(n)
+    #res = [fibonacci2(n) for n in range(30)]
+    t1 = time()
+    print(n, res, format(t1-t0, '0.6f'))
+
+if __name__=='__main__':
+    #test()
+    chronograph()

attic/decorators/local_demo.py

@@ -0,0 +1,63 @@
+"""
+>>> f1(3)
+>>> b = 8
+>>> f1(3)
+a = 3
+b = 8
+>>> f2(3)
+Traceback (most recent call last):
+  ...
+UnboundLocalError: local variable 'b' referenced before assignment
+>>> f3(3)
+a = 3
+b = 7
+b = 6
+>>> b = -5
+>>> ff = f4()
+>>> ff(3)
+a = 3
+b = 11
+b = 6
+>>> print('b =', b)
+b = -5
+"""
+
+def f1(a):
+    print('a =', a)
+    print('b =', b)
+
+def f2(a):
+    print('a =', a)
+    print('b =', b)
+    b = a * 10
+    print('b =', b)
+
+def f3(a):
+    global b
+    print('a =', a)
+    print('b =', b)
+    b = a * 10
+    print('b =', b)
+
+def f3b(a):
+    nonlocal b
+    print('a =', a)
+    print('b =', b)
+    b = a * 10
+    print('b =', b)
+
+def f4():
+    b = 11
+    def f5(a):
+        nonlocal b
+        print('a =', a)
+        print('b =', b)
+        b = a * 2
+        print('b =', b)
+    return f5
+
+import doctest
+doctest.testmod(optionflags=doctest.ELLIPSIS | doctest.NORMALIZE_WHITESPACE)
+
+
+

attic/decorators/stacked_demo.py

@@ -0,0 +1,27 @@
+def d1(f):
+    def wrapped():
+        print('d1/wrapped')
+        return f()
+    return wrapped
+
+
+def d2(f):
+    def wrapped():
+        print('d2/wrapped')
+        return f()
+    return wrapped
+
+
+@d1
+@d2
+def f():
+    print('f')
+
+f()
+
+def g():
+    print('g')
+
+g = d1(d2(g))
+
+g()