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When saving, how can you check if a field has changed?
...
Essentially, you want to override the __init__ method of models.Model so that you keep a copy of the original value. This makes it so that you don't have to do another DB lookup (which is always a good thing).
class Person(models.Model):
name = models.CharF...
How to process SIGTERM signal gracefully?
...n to use solution:
import signal
import time
class GracefulKiller:
kill_now = False
def __init__(self):
signal.signal(signal.SIGINT, self.exit_gracefully)
signal.signal(signal.SIGTERM, self.exit_gracefully)
def exit_gracefully(self,signum, frame):
self.kill_now = True
if __name...
How to import a module given its name as string?
...hat's pretty much how you do it.
For newer versions, see importlib.import_module for Python 2 and and Python 3.
You can use exec if you want to as well.
Or using __import__ you can import a list of modules by doing this:
>>> moduleNames = ['sys', 'os', 're', 'unittest']
>>> m...
How to find out if you're using HTTPS without $_SERVER['HTTPS']
I've seen many tutorials online that says you need to check $_SERVER['HTTPS'] if the server is connection is secured with HTTPS. My problem is that on some of the servers I use, $_SERVER['HTTPS'] is an undefined variable that results in an error. Is there another variable I can check that should...
How to list all functions in a Python module?
...n example with inspect:
from inspect import getmembers, isfunction
from my_project import my_module
functions_list = [o for o in getmembers(my_module) if isfunction(o[1])]
getmembers returns a list of (object_name, object_type) tuples.
You can replace isfunction with any of the other isXXX func...
How to convert JSON data into a Python object
...E
With Python3, you can do it in one line, using SimpleNamespace and object_hook:
import json
from types import SimpleNamespace
data = '{"name": "John Smith", "hometown": {"name": "New York", "id": 123}}'
# Parse JSON into an object with attributes corresponding to dict keys.
x = json.loads(data, ...
Shared-memory objects in multiprocessing
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@max Use a closure. The function given to apply_async should reference the shared object in scope directly instead of through its arguments.
– Francis Avila
Feb 3 '15 at 22:44
...
How can I remove an element from a list, with lodash?
...in the comments, more idiomatic and lodashy way to do this would be to use _.remove, like this
_.remove(obj.subTopics, {
subTopicId: stToDelete
});
Apart from that, you can pass a predicate function whose result will be used to determine if the current element has to be removed or not.
_.rem...
CoInitialize浅析一 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
... push [ebp+8] ; pvReserved
769B2A2E call _CoInitializeEx@8 ; CoInitializeEx(x,x)
769B2A33 pop ebp
769B2A34 retn 4
可以看到，其中的实现还是比较简单的，它只是简单地调用了CoInitializeEx，将第二个...
Show current assembly instruction in GDB
...───────────────┐
│0x7ffff740d756 <__libc_start_main+214> mov 0x39670b(%rip),%rax #│
│0x7ffff740d75d <__libc_start_main+221> mov 0x8(%rsp),%rsi │
│0x7ffff740d762 <__libc_start_main+226> mov 0x14(%rsp)...