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In the shell, what does “ 2>&1 ” mean?
...ing both streams to the same destination.
Here is how the file descriptor table looks like after Bash has redirected both streams:
As you can see, both stdout and stderr now point to file. So anything written to stdout and stderr gets written to file.
There are several ways to redirect both str...
SQL Server Escape an Underscore
...teral character, enclose the wildcard character in brackets. The following table shows several examples of using the LIKE keyword and the [ ] wildcard characters.
For your case:
... LIKE '%[_]d'
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How to store a dataframe using Pandas
...and read_pickle respectively).
Another popular choice is to use HDF5 (pytables) which offers very fast access times for large datasets:
store = HDFStore('store.h5')
store['df'] = df # save it
store['df'] # load it
More advanced strategies are discussed in the cookbook.
Since 0.13 there's...
What methods of ‘clearfix’ can I use?
...one css statement. Additionally, using display: block (instead of display: table) allows margins to collapse properly when elements with clearfix are siblings.
.container::after {
content: "";
display: block;
clear: both;
}
This is the most modern version of the clearfix.
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Older...
What is the most efficient way to store a list in the Django models?
...be better expressed as a one-to-many foreign key relationship to a Friends table? I understand that myFriends are just strings but I would think that a better design would be to create a Friend model and have MyClass contain a foreign key realtionship to the resulting table.
...
NSLog the method name with Objective-C in iPhone
...t because the Objective-C runtime is dynamic, it's actually using a lookup table to figure out which method on which class to call so a char* is convenient since methods are represented as strings in the lookup table.
– Jack Lawrence
Nov 7 '12 at 16:42
...
How to read data when some numbers contain commas as thousand separator?
...
You can have read.table or read.csv do this conversion for you semi-automatically. First create a new class definition, then create a conversion function and set it as an "as" method using the setAs function like so:
setClass("num.with.commas...
MYSQL OR vs IN performance
...s the same.
$t = microtime(true);
for($i=0; $i<10000; $i++):
$q = DB::table('users')->where('id',1)
->orWhere('id',2)
->orWhere('id',3)
->orWhere('id',4)
->orWhere('id',5)
->orWhere('id',6)
->orWhere('id',7)
->orWhere('id',8)
->orWhere(...
Why should C++ programmers minimize use of 'new'?
...omposes. It scales.
If you use the Line class as a building block:
class Table
{
Line borders[4];
};
Then
int main ()
{
Table table;
}
allocates four std::string instances, four Line instances, one Table instance and all the string's contents and everything is freed automagically...
How to find the statistical mode?
... hope it's helpful. It is also what I was thinking anyways. You'll want to table() the data, sort and then pick the first name. It's hackish but should work.
names(sort(-table(x)))[1]
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