update from Atlas

Author: ramalho

.gitignore

@@ -1,3 +1,5 @@
+concurrency/flags/img/
+
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]

attributes/exists_truthy.py

@@ -0,0 +1,43 @@
+import timeit
+
+def exists_and_truthy_hasattr(obj, attr_name):
+    if hasattr(obj, attr_name):
+        return bool(getattr(obj, attr_name))
+    else:
+        return False
+
+def exists_and_truthy_getattr(obj, attr_name):
+    return bool(getattr(obj, attr_name, False))
+
+def exists_and_truthy_tryget(obj, attr_name):
+    try:
+        return bool(getattr(obj, attr_name))
+    except AttributeError:
+        return False
+
+
+class Gizmo:
+    def __init__(self):
+        self.gadget = True
+
+gizmo = Gizmo()
+
+test_keys = 'hasattr', 'getattr', 'tryget'
+
+def average(timings):
+    sample = timings[1:-1]
+    return sum(sample) / len(sample)
+
+def do_tests():
+    for test_key in test_keys:
+        func_name = 'exists_and_truthy_' + test_key
+        test = func_name + '(gizmo, "gadget")'
+        setup = 'from __main__ import gizmo, ' + func_name
+        elapsed = average(timeit.repeat(test, repeat=5, setup=setup))
+        print(test_key.rjust(7), format(elapsed, '0.5f'))
+
+if __name__ == '__main__':
+    do_tests()
+    del gizmo.gadget
+    do_tests()
+

attributes/hasattr.py

@@ -0,0 +1,44 @@
+import timeit
+
+test_hasattr = """
+if hasattr(gizmo, 'gadget'):
+    feature = gizmo.gadget
+else:
+    feature = None
+"""
+
+test_getattr = """
+feature = getattr(gizmo, 'gadget', None)
+"""
+
+test_tryget = """
+try:
+    feature = getattr(gizmo, 'gadget')
+except AttributeError:
+    feature = None
+"""
+
+
+class Gizmo:
+    def __init__(self):
+        self.gadget = True
+
+gizmo = Gizmo()
+
+test_keys = 'hasattr', 'getattr', 'tryget'
+
+
+def test():
+    for test_key in test_keys:
+        test_name = 'test_' + test_key
+        test = globals()[test_name]
+        setup = 'from __main__ import gizmo'
+        t_present = min(timeit.repeat(test, setup=setup))
+        del gizmo.gadget
+        t_absent = min(timeit.repeat(test, setup=setup))
+        gizmo.gadget = True
+        print('{:7}  {:.3f}  {:.3f}'.format(test_key, t_present, t_absent))
+
+if __name__ == '__main__':
+    test()
+

concurrency/flags/countryflags.py

@@ -16,7 +16,11 @@
 # Vaurien
 VAURIEN_URL = 'http://localhost:8000/ciaflags/{gec}.gif'
 
-BASE_URL = VAURIEN_URL
+SOURCE_URLS = {
+    'CIA' : CIA_URL,
+    'NGINX' : NGINX_URL,
+    'VAURIEN' : VAURIEN_URL,
+}
 
 DEST_PATH_NAME = 'img/{cc}.gif'
 
@@ -34,8 +38,9 @@ def _load():
             cc2gec[iso_cc] = gec
 
 
-def flag_url(iso_cc):
-    return BASE_URL.format(gec=cc2gec[iso_cc].lower())
+def flag_url(iso_cc, source='CIA'):
+    base_url = SOURCE_URLS[source.upper()]
+    return base_url.format(gec=cc2gec[iso_cc].lower())
 
 def iso_file_name(iso_cc):
     return DEST_PATH_NAME.format(cc=iso_cc.lower())

concurrency/flags/getsequential.py

@@ -5,16 +5,16 @@
 
 times = {}
 
-def fetch(iso_cc):
-    resp = requests.get(cf.flag_url(iso_cc))
+def fetch(iso_cc, source):
+    resp = requests.get(cf.flag_url(iso_cc, source))
     if resp.status_code != 200:
         resp.raise_for_status()
     file_name = cf.iso_file_name(iso_cc)
     with open(file_name, 'wb') as img:
         written = img.write(resp.content)
     return written, file_name
 
-def main():
+def main(source):
     pending = sorted(cf.cc2name)
     to_download = len(pending)
     downloaded = 0
@@ -23,7 +23,7 @@ def main():
         print('get:', iso_cc)
         try:
             times[iso_cc] = [time.time() - t0]
-            octets, file_name = fetch(iso_cc)
+            octets, file_name = fetch(iso_cc, source)
             times[iso_cc].append(time.time() - t0)
             downloaded += 1
             print('\t--> {}: {:5d} bytes'.format(file_name, octets))
@@ -36,7 +36,14 @@ def main():
         print('{}\t{:.6g}\t{:.6g}'.format(iso_cc, start, end))
 
 if __name__ == '__main__':
-    main()
+    import argparse
+
+    source_names = ', '.join(sorted(cf.SOURCE_URLS))
+    parser = argparse.ArgumentParser(description='Download flag images.')
+    parser.add_argument('source', help='one of: ' + source_names)
+
+    args = parser.parse_args()
+    main(args.source)
 
 """
 From cia.gov:
@@ -53,4 +60,4 @@ def main():
 real    1m40.519s
 user    0m1.103s
 sys     0m0.243s
-"""
+"""

concurrency/flags/getthreadpool.py

@@ -11,15 +11,15 @@
 
 times = {}
 
-def main(num_threads):
+def main(source, num_threads):
     pool = futures.ThreadPoolExecutor(num_threads)
     pending = {}
     t0 = time.time()
     # submit all jobs
     for iso_cc in sorted(cf.cc2name):
         print('get:', iso_cc)
         times[iso_cc] = [time.time() - t0]
-        job = pool.submit(fetch, iso_cc)
+        job = pool.submit(fetch, iso_cc, source)
         pending[job] = iso_cc
     to_download = len(pending)
     downloaded = 0
@@ -39,18 +39,23 @@ def main(num_threads):
         print('{}\t{:.6g}\t{:.6g}'.format(iso_cc, start, end))
 
 if __name__ == '__main__':
-    if len(sys.argv) == 2:
-        num_threads = int(sys.argv[1])
-    else:
-        num_threads = DEFAULT_NUM_THREADS
-    main(num_threads)
+    import argparse
+
+    source_names = ', '.join(sorted(cf.SOURCE_URLS))
+    parser = argparse.ArgumentParser(description='Download flag images.')
+    parser.add_argument('source', help='one of: ' + source_names)
+    parser.add_argument('-t', '--threads', type=int, default=DEFAULT_NUM_THREADS,
+                   help='number of threads (default: %s)' % DEFAULT_NUM_THREADS)
+
+    args = parser.parse_args()
+    main(args.source, args.threads)
 
 """
-From localhost nginx:
-real    0m1.163s
-user    0m1.001s
-sys     0m0.289s
+From CIA, 1 thread:
+real    2m0.832s
+user    0m4.685s
+sys     0m0.366s
 
 
 
-"""
+"""

concurrency/flags/img.zip

@@ -0,0 +1,50 @@
+"""
+Spreadsheet example adapted from Raymond Hettinger's `recipe`__
+
+__ http://code.activestate.com/recipes/355045-spreadsheet/
+
+Demonstration::
+
+    >>> from math import sin, pi
+    >>> ss = Spreadsheet(sin=sin, pi=pi, abs=abs)
+    >>> ss['a1'] = '-5'
+    >>> ss['a2'] = 'a1*6'
+    >>> ss['a3'] = 'a2*7'
+    >>> ss['a3']
+    -210
+    >>> ss['b1'] = 'sin(pi/4)'
+    >>> ss['b1']  # doctest:+ELLIPSIS
+    0.707106781186...
+    >>> ss.getformula('b1')
+    'sin(pi/4)'
+    >>> ss['c1'] = 'abs(a2)'
+    >>> ss['c1']
+    30
+    >>> ss['c2'] = 'len(a2)'
+    >>> ss['c2']
+    Traceback (most recent call last):
+      ...
+    NameError: name 'len' is not defined
+    >>> ss['d1'] = '3*'
+    >>> ss['d1']
+    Traceback (most recent call last):
+      ...
+    SyntaxError: unexpected EOF while parsing
+"""
+
+
+class Spreadsheet:
+
+    def __init__(self, **tools):
+        self._cells = {}
+        self._tools = {'__builtins__' : {}}
+        self._tools.update(tools)
+
+    def __setitem__(self, key, formula):
+        self._cells[key] = formula
+
+    def getformula(self, key):
+        return self._cells[key]
+
+    def __getitem__(self, key):
+        return eval(self._cells[key], self._tools, self)

metaprog/spreadsheet.py

@@ -0,0 +1,54 @@
+"""
+Spreadsheet example adapted from Raymond Hettinger's `recipe`__
+
+__ http://code.activestate.com/recipes/355045-spreadsheet/
+
+Demonstration::
+
+    >>> from math import sin, pi
+    >>> ss = Spreadsheet(sin=sin, pi=pi, abs=abs)
+    >>> ss['a1'] = '-5'
+    >>> ss['a2'] = 'a1*6'
+    >>> ss['a3'] = 'a2*7'
+    >>> ss['a3']
+    -210
+    >>> ss['b1'] = 'sin(pi/4)'
+    >>> ss['b1']  # doctest:+ELLIPSIS
+    0.707106781186...
+    >>> ss.getformula('b1')
+    'sin(pi/4)'
+    >>> ss['c1'] = 'abs(a2)'
+    >>> ss['c1']
+    30
+    >>> ss['c2'] = 'len(a2)'
+    >>> ss['c2']
+    Traceback (most recent call last):
+      ...
+    NameError: name 'len' is not defined
+    >>> ss['d1'] = '3*'
+    Traceback (most recent call last):
+      ...
+    SyntaxError: unexpected EOF while parsing ['d1'] = '3*'
+"""
+
+
+class Spreadsheet:
+
+    def __init__(self, **tools):
+        self._cells = {}
+        self._tools = {'__builtins__' : {}}
+        self._tools.update(tools)
+
+    def __setitem__(self, key, formula):
+        try:
+            compile(formula, '<__setitem__>', 'eval')
+        except SyntaxError as exc:
+            msg = '{} [{!r}] = {!r}'.format(exc.msg, key, formula)
+            raise SyntaxError(msg)
+        self._cells[key] = formula
+
+    def getformula(self, key):
+        return self._cells[key]
+
+    def __getitem__(self, key):
+        return eval(self._cells[key], self._tools, self)