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Why does ~True result in -2?
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int(True) is 1.
1 is:
00000001
and ~1 is:
11111110
Which is -2 in Two's complement1
1 Flip all the bits, add 1 to the resulting number and interpret the result as a binary representation of the magnitude and add a negative ...
Can I set a breakpoint on 'memory access' in GDB?
I am running an application through gdb and I want to set a breakpoint for any time a specific variable is accessed / changed. Is there a good method for doing this? I would also be interested in other ways to monitor a variable in C/C++ to see if/when it changes.
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What difference is there between WebClient and HTTPWebRequest classes in .NET?
What difference is there between the WebClient and the HttpWebRequest classes in .NET? They both do very similar things. In fact, why weren't they merged into one class (too many methods/variables etc may be one reason but there are other classes in .NET which breaks that rule).
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Running a specific test case in Django when your app has a tests directory
The Django documentation ( http://docs.djangoproject.com/en/1.3/topics/testing/#running-tests ) says that you can run individual test cases by specifying them:
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How to create a new database using SQLAlchemy?
Using SQLAlchemy, an Engine object is created like this:
4 Answers
4
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When to use pip requirements file versus install_requires in setup.py?
I'm using pip with virtualenv to package and install some Python libraries.
4 Answers
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Search an Oracle database for tables with specific column names?
We have a large Oracle database with many tables. Is there a way I can query or search to find if there are any tables with certain column names?
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Bash, no-arguments warning, and case decisions
... ; then
echo 'some message'
exit 0
fi
case "$1" in
1) echo 'you gave 1' ;;
*) echo 'you gave something else' ;;
esac
The Advanced Bash-Scripting Guide is pretty good. In spite of its name, it does treat the basics.
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Time complexity of Sieve of Eratosthenes algorithm
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Your n/2 + n/3 + n/5 + … n/97 is not O(n), because the number of terms is not constant. [Edit after your edit: O(n2) is too loose an upper bound.] A loose upper-bound is n(1+1/2+1/3+1/4+1/5+1/6+…1/n) (sum of reciprocals of ...
Creating functions in a loop
I'm trying to create functions inside of a loop:
2 Answers
2
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