djsmith42

def do_something(some_list=[]):
    some_list.append('some item')
    print some_list

djsmith42

>>> do_something()
['some item']
>>> do_something()
['some item', 'some item']
>>> do_something()
['some item', 'some item', 'some item']
>>> do_something()
['some item', 'some item', 'some item', 'some item']
>>> 

djsmith42

>>> do_something(['my item'])
['my item', 'some item']
>>> do_something(['my item'])
['my item', 'some item']
>>> do_something(['my item'])
['my item', 'some item']
>>> 

djsmith42

>>> do_something.func_defaults
(['some item'],)
>>> 

djsmith42

>>> do_something.func_defaults = ([42],)
>>> do_something()
[42, 'some item']
>>> 

djsmith42

from contextlib import contextmanager
import sys, os

@contextmanager
def suppress_stdout():
    with open(os.devnull, "w") as devnull:
        old_stdout = sys.stdout
        sys.stdout = devnull
        try:  
            yield

djsmith42

print "You can see this"
with suppress_stdout():
    print "You cannot see this"
print "And you can see this again"

djsmith42

import itertools
for a, b, c, d, e, f in itertools.product(range(1, 10), range(1, 10), range(1, 10), range(1, 10), range(1, 10), range(1, 10)):
    if (a + b + c == 18 and
        d + e + f == 18 and
        a + d == b + e and
        b + e == c + f and
        int(str(e) + str(f)) in [16, 25, 36, 49, 64, 81] and
        len(set([a, b, c, d, e, f])) == 6):
        print a, b, c, d, e, f

djsmith42

scale 562949953421312
bad at 1125899906842624 0x4000000000000 0b100000000000000000000000000000000000000000000000000

scale 281474976710656
bad at 562949953421312 0x2000000000000 0b10000000000000000000000000000000000000000000000000

scale 140737488355328
bad at 281474976710656 0x1000000000000 0b1000000000000000000000000000000000000000000000000

scale 70368744177664

djsmith42

void my_function() {
   char *data = malloc(1024);
   return; // oops! memory leak
}