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@property retain, assign, copy, nonatomic in Objective-C
...age is no longer working. So, here is what I've learned in my (very) short time coding in Objective-C:
nonatomic vs. atomic
- "atomic" is the default. Always use "nonatomic". I don't know why, but the book I read said there is "rarely a reason" to use "atomic". (BTW: The book I read is the BNR "iOS...
How do I migrate a model out of one django app and into a new one?
...cy is set South will not guarantee that the common_cat table exists at the time when specific/0003_create_cat is run, throwing an django.db.utils.OperationalError: no such table: common_cat error at you.
South runs migrations in lexicographical order unless dependency is explicitly set. Since commo...
In C#, what happens when you call an extension method on a null object?
... this argument is null:
default(string).MyExtension();
Works well at runtime, but produces the warning "Expression will always cause a System.NullReferenceException, because the default value of string is null".
share
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Returning a C string from a function
..., especially 'down the road'.
In short, although my answer is correct - 9 times out of 10 you'll end up with a program that crashes if you use it that way, especially if you think it's 'good practice' to do it that way. In short: It's generally not.
For example, imagine some time in the future, th...
Why would one use the Publish/Subscribe pattern (in JS/jQuery)?
... me to the publish/subscribe pattern (in JS/jQuery), but I'm having a hard time getting to grips with why one would use this pattern over 'normal' JavaScript/jQuery.
...
Finding a substring within a list in Python [duplicate]
...ll lists, it doesn't make a difference, but consider this example:
import timeit
mylist = ['abc123'] + ['xyz123']*1000
sub = 'abc'
timeit.timeit('[s for s in mylist if sub in s]', setup='from __main__ import mylist, sub', number=100000)
# for me 7.949463844299316 with Python 2.7, 8.56884094499400...
How to recursively find the latest modified file in a directory?
...ard for sort to keep everything in memory.
%T@ gives you the modification time like a unix timestamp, sort -n sorts numerically, tail -1 takes the last line (highest timestamp), cut -f2 -d" " cuts away the first field (the timestamp) from the output.
Edit: Just as -printf is probably GNU-only, ajr...
python date of the previous month
...
datetime and the datetime.timedelta classes are your friend.
find today.
use that to find the first day of this month.
use timedelta to backup a single day, to the last day of the previous month.
print the YYYYMM string you're ...
Case insensitive 'in'
...ame in USERNAMES) would create only a generator and one needed string at a time - massive memory savings if you're doing this operation a lot. (even more savings, if you simply create a list of lowercase usernames that you reuse for checking every time)
– viraptor
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How can I use threading in Python?
...r() is better style for current Python. Super was relatively recent at the time that I provided this answer, hence calling directly to the super class rather than using super(). I'll update this to use super, though.
– Michael Aaron Safyan
Mar 6 '14 at 11:16
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