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How can I read a large text file line by line using Java?
...null) {
// process the line.
}
}
You can read the data faster if you assume there is no character encoding. e.g. ASCII-7 but it won't make much difference. It is highly likely that what you do with the data will take much longer.
EDIT: A less common pattern to use which avoids the sco...
Running multiple commands with xargs
...ell-like (but not quite shell-compatible) parsing to the stream it reads. (If you don't have GNU xargs, you can use tr '\n' '\0' <a.txt | xargs -0 ... to get line-oriented reading without -d).
The _ is a placeholder for $0, such that other data values added by xargs become $1 and onward, which ha...
What's the fastest algorithm for sorting a linked list?
I'm curious if O(n log n) is the best a linked list can do.
13 Answers
13
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Create a dictionary on a list with grouping
...ionary(gdc => gdc.Key, gdc => gdc.ToList());
You'd make it shorter if you used shorter variable names too, of course :)
However, might I suggest that a Lookup might be more appropriate? A Lookup is basically a dictionary from a key to an IEnumerable<T> - unless you really need the val...
How to use jQuery to select a dropdown option?
I was wondering if it’s possible to get jQuery to select an <option> , say the 4th item, in a dropdown box?
13 Ans...
How to update PATH variable permanently from Windows command line?
If I execute set PATH=%PATH%;C:\\Something\\bin from the command line ( cmd.exe ) and then execute echo %PATH% I see this string added to the PATH. If I close and open the command line, that new string is not in PATH.
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How to drop columns by name in a data frame
I have a large data set and I would like to read specific columns or drop all the others.
11 Answers
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Logical Operators, || or OR?
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There is no "better" but the more common one is ||. They have different precedence and || would work like one would expect normally.
See also: Logical operators (the following example is taken from there):
// The result of the expression (false || true) is assigned to $e
// Acts like: ...
Jackson overcoming underscores in favor of camel-case
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@RyanShillington - Correct me if I'm wrong, but this is your only option if the JSON string you are parsing from does not use a consistent format, i.e., uses both camelCase and underscore?
– DavidR
Nov 16 '15 at 23:4...
select and update database record with a single queryset
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Just a fair warning... if you use the update method like this then any signals attached to that model or other "code stuff" won't run against the objects. Just a pointer from someone who got burned :)
– DMac the Destroyer
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