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What is the purpose of Flask's context stacks?
... up models
db.create_all()
In this case, the Flask-SQLAlchemy extension knows about the app application, but during create_all() it will throw an error complaining about there not being an application context. This error is justified; you never told Flask what application it should be dealing with...
Sleep until a specific time/date
...anted to wait until next week:
expr `date -d "next week" +%s` - `date -d "now" +%s`
Just substitute "next week" with whatever date you'd like to wait for, then assign this expression to a value, and sleep for that many seconds:
startTime=$(date +%s)
endTime=$(date -d "next week" +%s)
timeToWait=...
Temporarily disable auto_now / auto_now_add
...odels.CharField(max_length=255)
updated_at = models.DateTimeField(auto_now=True, auto_now_add=True)
# my tests
foo = FooBar.objects.get(pk=1)
# force a timestamp
lastweek = datetime.datetime.now() - datetime.timedelta(days=7)
FooBar.objects.filter(pk=foo.pk).update(updated_at=lastweek)
# do...
What is __init__.py for?
...make two blank files, the init.py file (with underscores) and datetime.py. Now open an interpreter, import sys, and issue sys.path.insert(0, '/path/to/datetime'), replacing that path with the path to whatever directory you just made. Now try something like from datetime import datetime;datetime.now(...
How does __proto__ differ from constructor.prototype?
...sheds full light over the matter
http://i.stack.imgur.com/KFzI3.png
I know I'm not the first one making this up but it was more interesting figuring it out that finding it :-). Anyway, after that I found e.g. this another diagram that I think says basicly the same:
Javascript object layout
The...
How to avoid having class data shared among instances?
...f.x
A change method sets self.temp
Pretty straight forward so far yeah? Now let's start playing around with this class. Let's initialize this class first:
a = A('Tesseract')
Now do the following:
>>> print(a.temp)
Skyharbor
>>> print(A.temp)
Skyharbor
Well, a.temp worked ...
How can I add new keys to a dictionary?
... value is in the end too. Anyway answer has been edited and is much better now. Updating with a dictionary is good when it's likely that it contains many items.
– Jean-François Fabre♦
Jan 20 at 16:26
...
How to convert DateTime? to DateTime
...ode.
DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate ?? DateTime.Now;
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Clang vs GCC for my Linux Development project
...cc (ah competition). They created a wiki page to showcase it here. gcc 4.8 now has quite good diagnostics as well (gcc 4.9x added color support). Clang is still in the lead, but the gap is closing.
Original:
For students, I would unconditionally recommend Clang.
The performance in terms of gene...
Replacing a 32-bit loop counter with 64-bit introduces crazy performance deviations with _mm_popcnt_
...will wait until dest is ready before executing. This false dependency is (now) documented by Intel as erratum HSD146 (Haswell) and SKL029 (Skylake)
Skylake fixed this for lzcnt and tzcnt.
Cannon Lake (and Ice Lake) fixed this for popcnt.
bsf/bsr have a true output dependency: output unmodified for...