![Tools%for%observa,on:%inspect
>>> import random
>>> import inspect
>>> print inspect.getsource(random.choice)
def choice(self, seq):
"""Choose a random element from a non-empty sequence."""
return seq[int(self.random() * len(seq))] # raises IndexError if seq is empty](https://image.slidesharecdn.com/exploringslides-160125004816/85/Exploring-slides-15-320.jpg)
![Tools%for%observa,on:%inspect
>>> import random
>>> import inspect
>>> print inspect.getsource(random.choice)
def choice(self, seq):
"""Choose a random element from a non-empty sequence."""
return seq[int(self.random() * len(seq))] # raises IndexError if seq is empty
>>> print inspect.getsource(list.append)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 701, in getsource
lines, lnum = getsourcelines(object)
File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 690, in getsourcelines
lines, lnum = findsource(object)
File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 526, in findsource
file = getfile(object)
File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 420, in getfile
'function, traceback, frame, or code object'.format(object))
TypeError: <method 'append' of 'list' objects> is not a module, class, method, function, traceback, frame, or code object
>>> # :(
github.com/punchagan/cinspect](https://image.slidesharecdn.com/exploringslides-160125004816/85/Exploring-slides-16-320.jpg)
Exploring slides
- 2. @akaptur
- 5. Contribu)ng
- 14. How$to$observe
- 15. Tools%for%observa,on:%inspect >>> import random >>> import inspect >>> print inspect.getsource(random.choice) def choice(self, seq): """Choose a random element from a non-empty sequence.""" return seq[int(self.random() * len(seq))] # raises IndexError if seq is empty
- 16. Tools%for%observa,on:%inspect >>> import random >>> import inspect >>> print inspect.getsource(random.choice) def choice(self, seq): """Choose a random element from a non-empty sequence.""" return seq[int(self.random() * len(seq))] # raises IndexError if seq is empty >>> print inspect.getsource(list.append) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 701, in getsource lines, lnum = getsourcelines(object) File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 690, in getsourcelines lines, lnum = findsource(object) File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 526, in findsource file = getfile(object) File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 420, in getfile 'function, traceback, frame, or code object'.format(object)) TypeError: <method 'append' of 'list' objects> is not a module, class, method, function, traceback, frame, or code object >>> # :( github.com/punchagan/cinspect
- 18. Tools%for%observa,on:%history%&%changelogs hg blame Python/ceval.c hg log -r ### -p
- 20. Tools%for%observa,on:%internal%structure >>> False is False is False
- 21. Tools%for%observa,on:%internal%structure >>> (False is False) is False
- 22. Tools%for%observa,on:%internal%structure >>> False is False is False True
- 23. Tools%for%observa,on:%internal%structure >>> False is False is False True >>> a < b < c True
- 24. Tools%for%observa,on:%internal%structure 1 0 LOAD_NAME 0 (False) 3 LOAD_NAME 0 (False) 6 DUP_TOP 7 ROT_THREE 8 COMPARE_OP 8 (is) 11 JUMP_IF_FALSE_OR_POP 23 14 LOAD_NAME 0 (False) 17 COMPARE_OP 8 (is) 20 JUMP_FORWARD 2 (to 25) >> 23 ROT_TWO 24 POP_TOP >> 25 POP_TOP 26 LOAD_CONST 0 (None) 29 RETURN_VALUE
- 25. Tools%for%observa,on:%internal%structure 1 0 LOAD_NAME 0 (a) 3 LOAD_NAME 1 (b) 6 DUP_TOP 7 ROT_THREE 8 COMPARE_OP 0 (<) 11 JUMP_IF_FALSE_OR_POP 23 14 LOAD_NAME 2 (c) 17 COMPARE_OP 0 (<) 20 JUMP_FORWARD 2 (to 25) >> 23 ROT_TWO 24 POP_TOP >> 25 POP_TOP 26 LOAD_CONST 0 (None) 29 RETURN_VALUE
- 28. Tools%for%science:%measurements e.g.$%meit $ python -m timeit -s "li = range(100)" "li.sort(reverse=True)" 1000000 loops, best of 3: 1.75 usec per loop $ python -m timeit -s "li = range(100)" "sorted(li, reverse=True)" 100000 loops, best of 3: 2.46 usec per loop
- 31. Observa(on+&+Experimenta(on+>+Reading+ the+code • Introspect+it • Examine+it+cri1cally • Watch+it+evolve • Measure+it • Test+it • Change+it • Poke+it+with+a+s1ck
- 32. Ques%ons
- 33. class Random(_random.Random): """Random number generator base class used by bound module functions. Used to instantiate instances of Random to get generators that don't share state.""" ... # Create one instance, seeded from current time, and export its methods # as module-level functions. The functions share state across all uses #(both in the user's code and in the Python libraries), but that's fine # for most programs and is easier for the casual user than making them # instantiate their own Random() instance. _inst = Random() seed = _inst.seed random = _inst.random randint = _inst.randint choice = _inst.choice ...