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Should I use 'has_key()' or 'in' on Python dicts?
...ng, I didn't see that. I suppose it's because x in d.keys() must construct and destroy a temporary object, complete with the memory allocation that entails, where x in d.keys() is just doing an arithmetic operation (computing the hash) and doing a lookup. Note that d.keys() is only about 10 times as...
How do I measure time elapsed in Java? [duplicate]
...answers posted so far are quite right.
If you are measuring elapsed time, and you want it to be correct, you must use System.nanoTime(). You cannot use System.currentTimeMillis(), unless you don't mind your result being wrong.
The purpose of nanoTime is to measure elapsed time, and the purpose of...
Count number of occurrences of a pattern in a file (even on same line)
...occurrences, use -o. Try this:
echo afoobarfoobar | grep -o foo | wc -l
And man grep of course (:
Update
Some suggest to use just grep -co foo instead of grep -o foo | wc -l.
Don't.
This shortcut won't work in all cases. Man page says:
-c print a count of matching lines
Difference in these...
Write a program to find 100 largest numbers out of an array of 1 billion numbers
... number in the queue (the head of the queue), remove the head of the queue and add the new number to the queue.
EDIT:
as Dev noted, with a priority queue implemented with a heap, the complexity of insertion to queue is O(logN)
In the worst case you get billionlog2(100) which is better than billion...
Timeout function if it takes too long to finish [duplicate]
...cript that loops through a text file containing URL:s that I want to visit and take screenshots of.
2 Answers
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How to print a linebreak in a python function?
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You can print a native linebreak using the standard os library
import os
with open('test.txt','w') as f:
f.write(os.linesep)
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What does set -e mean in a bash script?
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From help set :
-e Exit immediately if a command exits with a non-zero status.
But it's considered bad practice by some (bash FAQ and irc freenode #bash FAQ authors). It's recommended to use:
trap 'do_something' ERR
to run do_something function when errors occur.
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Start / Stop a Windows Service from a non-Administrator user account
I have a WindowsService named, say, BST. And I need to give a non-Administrator user, UserA, the permissions to Start/Stop this particular service. My service runs on a variety of Windows OS, starting from Windows Server 2003 to Windows 7.
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CFLAGS vs CPPFLAGS
I understand that CFLAGS (or CXXFLAGS for C++) are for the compiler, whereas CPPFLAGS is used by the preprocessor.
4 Answer...
Git pull a certain branch from GitHub
...have a project with multiple branches. I've been pushing them to GitHub , and now that someone else is working on the project I need to pull their branches from GitHub. It works fine in master. But say that someone created a branch xyz . How can I pull branch xyz from GitHub and merge it into br...