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Get difference between two lists
...t
In [5]: set([1, 2]) - set([2, 3])
Out[5]: set([1])
where you might expect/want it to equal set([1, 3]). If you do want set([1, 3]) as your answer, you'll need to use set([1, 2]).symmetric_difference(set([2, 3])).
shar...
Which SQL query is faster? Filter on Join criteria or Where clause?
...is will look like this:
SELECT *
FROM TableA a
LEFT JOIN
TableXRef x
ON x.TableAID = a.ID
AND a.ID = 1
LEFT JOIN
TableB b
ON x.TableBID = b.ID
or this:
SELECT *
FROM TableA a
LEFT JOIN
TableXRef x
ON x.TableAID = a.ID
LEFT JOIN
Table...
What's the simplest way to test whether a number is a power of 2 in C++?
...eturn true for n=0, so if that is possible, you will want to check for it explicitly.
http://www.graphics.stanford.edu/~seander/bithacks.html has a large collection of clever bit-twiddling algorithms, including this one.
sh...
What does “SyntaxError: Missing parentheses in call to 'print'” mean in Python?
... error message means that you are attempting to use Python 3 to follow an example or run a program that uses the Python 2 print statement:
print "Hello, World!"
The statement above does not work in Python 3. In Python 3 you need to add parentheses around the value to be printed:
print("Hello...
Can a recursive function be inline?
... }
else
{
return n * factorial(n - 1);
}
}
int f(int x)
{
return factorial(x);
}
into this code:
int factorial(int n)
{
if (n <= 1)
{
return 1;
}
else
{
return n * factorial(n - 1);
}
}
int f(int x)
{
if (x <= 1)
{
...
delegate keyword vs. lambda notation
... Action) you'll get an anonymous delegate.
If you assign the lambda to an Expression type, you'll get an expression tree instead of a anonymous delegate. The expression tree can then be compiled to an anonymous delegate.
Edit:
Here's some links for Expressions.
System.Linq.Expression.Expression...
How can I rename a field for all documents in MongoDB?
...the docs which contain the property:
db.foo.update({"name.additional": {$exists: true}}, {$rename:{"name.additional":"name.last"}}, false, true);
The false, true in the method above are: { upsert:false, multi:true }. You need the multi:true to update all your records.
Or you can use the former w...
SELECT * FROM X WHERE id IN (…) with Dapper ORM
...n the list of values for the IN clause is coming from business logic? For example let's say I have a query:
9 Answers
...
How to find the operating system version using JavaScript?
...meTypes = [object MimeTypeArray]
# oscpu = Windows NT 5.1
# vendor = Firefox
# vendorSub = 1.0.7
# product = Gecko
# productSub = 20050915
# plugins = [object PluginArray]
# securityPolicy =
# userAgent = Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.12) Gecko/20050915 Firefox/1.0.7
# cooki...
Integrating the ZXing library directly into my Android application
...nstall Apache Ant - (See this YouTube video for config help)
Download the ZXing source from ZXing homepage and extract it
With the use of Windows Commandline (Run->CMD) navigate to the root directory of the downloaded zxing src.
In the commandline window - Type ant -f core/build.xml press enter a...