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Where should signal handlers live in a django project?
...ke:
yourapp/signals/handlers.py:
from django.db.models.signals import pre_save
from django.dispatch import receiver
from myapp.models import MyModel
@receiver(pre_save, sender=MyModel)
def my_handler(sender, **kwargs):
pass
The best place to register your signal handler is then in the AppCo...
Python error “ImportError: No module named”
... your comments to orip's post, I guess this is what happened:
You edited __init__.py on windows.
The windows editor added something non-printing, perhaps a carriage-return (end-of-line in Windows is CR/LF; in unix it is LF only), or perhaps a CTRL-Z (windows end-of-file).
You used WinSCP to copy t...
ruby send method passing multiple parameters
...
send("i_take_multiple_arguments", *[25.0,26.0]) #Where star is the "splat" operator
or
send(:i_take_multiple_arguments, 25.0, 26.0)
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Empty set literal?
...>> print(s)
set()
this is basically a more condensed way of doing {_ for _ in ()}, but, don't do this.
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What's the difference between echo, print, and print_r in PHP?
I use echo and print_r much, and almost never use print .
11 Answers
11
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How can I swap positions of two open files (in splits) in vim?
...
Starting with this:
____________________
| one | two |
| | |
| |______|
| | three|
| | |
|___________|______|
Make 'three' the active window, then issue the command ctrl+w J. This moves ...
Python division
...t:
>>> float(10 - 20) / (100 - 10)
-0.1111111111111111
or from __future__ import division, which the forces / to adopt Python 3.x's behavior that always returns a float.
>>> from __future__ import division
>>> (10 - 20) / (100 - 10)
-0.1111111111111111
...
How to automatically generate a stacktrace when my program crashes
...nclude <unistd.h>
void handler(int sig) {
void *array[10];
size_t size;
// get void*'s for all entries on the stack
size = backtrace(array, 10);
// print out all the frames to stderr
fprintf(stderr, "Error: signal %d:\n", sig);
backtrace_symbols_fd(array, size, STDERR_FILENO)...
How to find the JVM version from a program?
...version "12" "1.8.0_201" "1.5.0_22" Java Runtime Environment version, which may be interpreted as a Runtime.Version
java.version.date "2019-03-19" ...
Is there a difference between “==” and “is”?
... most cases this logic is true, but it relies on the implementation of the __eq__ special method. As the docs say,
The default behavior for equality comparison (== and !=) is based on
the identity of the objects. Hence, equality comparison of instances
with the same identity results in equa...