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Difference between dispatch_async and dispatch_sync on serial queue?
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for this code
dispatch_async(_serialQueue, ^{ printf("1"); });
printf("2");
dispatch_async(_serialQueue, ^{ printf("3"); });
printf("4");
It may print 2413 or 2143 or 1234 but 1 always before 3
for this code
dispatch_sync(_serialQueue, ^{ printf("1"); });
printf("2");
dispatch_sync(_serialQu...
Best way to iterate through a Perl array
...ng of the array elements occurs. ($_ is aliased to the element in #1, but #2 and #3 actually copy the scalars from the array.)
#5 might be similar.
In terms memory usage: They're all the same except for #5.
for (@a) is special-cased to avoid flattening the array. The loop iterates over the indexes...
How to set up Spark on Windows?
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edited Mar 26 '15 at 18:57
answered Aug 25 '14 at 12:19
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Sublime Text 2 and 3: open the same file multiple times
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answered Feb 24 '14 at 15:44
RichardRichard
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Python set to list
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245
Your code does work (tested with cpython 2.4, 2.5, 2.6, 2.7, 3.1 and 3.2):
>>> a = s...
How to check Django version
...ython and Django for our application. So I have two versions of Python, 2.6 and 2.7. Now I have installed Django. I could run the sample application for testing Django succesfuly. But how do I make sure whether Django uses the 2.6 or 2.7 version and what version of modules Django uses?
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How to log cron jobs?
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* * * * * myjob.sh >> /var/log/myjob.log 2>&1
will log all output from the cron job to /var/log/myjob.log
You might use mail to send emails. Most systems will send unhandled cron job output by email to root or the corresponding user.
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sys.argv[1] meaning in script
...ion
import sys
print(sys.argv, len(sys.argv))
The script requires Python 2.6 or later. If you call this script print_args.py, you can invoke it with different arguments to see what happens.
> python print_args.py
['print_args.py'] 1
> python print_args.py foo and bar
['print_args.py', 'foo...
How to add texture to fill colors in ggplot2
...s greys when using a black and white printer. I searched the online ggplot2 documentation but didn't see anything about adding textures to fill colors. Is there an official ggplot2 way to do this or does anyone have a hack that they use? By textures I mean things like diagonal bars, reverse diag...
A better similarity ranking algorithm for variable length strings
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