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What are the differences between NP, NP-Complete and NP-Hard?
...njunction (ANDs) of 3-clause disjunctions (ORs), statements of the form
(x_v11 OR x_v21 OR x_v31) AND
(x_v12 OR x_v22 OR x_v32) AND
... AND
(x_v1n OR x_v2n OR x_v3n)
where each x_vij is a boolean variable or the negation of a variable from a finite predefined list (x_1, x...
Enable access control on simple HTTP server
...mport sys
class CORSRequestHandler (SimpleHTTPRequestHandler):
def end_headers (self):
self.send_header('Access-Control-Allow-Origin', '*')
SimpleHTTPRequestHandler.end_headers(self)
if __name__ == '__main__':
test(CORSRequestHandler, HTTPServer, port=int(sys.argv[1]) if le...
Django 1.7 - makemigrations not detecting changes
... out) listed in the documentation:
python manage.py makemigrations your_app_label
The documentation does not make it obvious that you need to add the app label to the command, as the first thing it tells you to do is python manage.py makemigrations which will fail. The initial migration is don...
What is a None value?
... this book?because his name is Jason R. Briggs.
– The_Diver
Oct 20 '13 at 18:52
...
#define macro for debug printing in C?
...
If you use a C99 or later compiler
#define debug_print(fmt, ...) \
do { if (DEBUG) fprintf(stderr, fmt, __VA_ARGS__); } while (0)
It assumes you are using C99 (the variable argument list notation is not supported in earlier versions). The do { ... } while (0...
How do I show the value of a #define at compile-time?
... This also works great with Xcode 8, e.g. replacing ABC with __IPHONE_9_3.
– funroll
Oct 11 '16 at 19:50
...
How to generate keyboard events in Python?
...om ctypes import wintypes
import time
user32 = ctypes.WinDLL('user32', use_last_error=True)
INPUT_MOUSE = 0
INPUT_KEYBOARD = 1
INPUT_HARDWARE = 2
KEYEVENTF_EXTENDEDKEY = 0x0001
KEYEVENTF_KEYUP = 0x0002
KEYEVENTF_UNICODE = 0x0004
KEYEVENTF_SCANCODE = 0x0008
MAPVK_VK_TO_VSC = 0
# ...
Does python have an equivalent to Java Class.forName()?
...honic way of doing it.
Here's a function that does what you want:
def get_class( kls ):
parts = kls.split('.')
module = ".".join(parts[:-1])
m = __import__( module )
for comp in parts[1:]:
m = getattr(m, comp)
return m
You can use the return value of this ...
How do I filter ForeignKey choices in a Django ModelForm?
...e fields named directly.
form.rate.queryset = Rate.objects.filter(company_id=the_company.id)
If you take the default ModelForm object, form.fields["rate"].queryset = ...
This is done explicitly in the view. No hacking around.
...
Python: How do I make a subclass from a superclass?
...
# Initialize using Parent
#
class MySubClass(MySuperClass):
def __init__(self):
MySuperClass.__init__(self)
Or, even better, the use of Python's built-in function, super() (see the Python 2/Python 3 documentation for it) may be a slightly better method of calling the parent for ...