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How to count TRUE values in a logical vector
...ic way to count the number of TRUE values in a logical vector? I can think of two ways:
8 Answers
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sed one-liner to convert all uppercase to lowercase?
...pper case
$ tr '[:lower:]' '[:upper:]' < input.txt > output.txt
Works using GNU sed (BSD sed doesn't support \L \U):
# Converts upper to lower case
$ sed -e 's/\(.*\)/\L\1/' input.txt > output.txt
# Converts lower to upper case
$ sed -e 's/\(.*\)/\U\1/' input.txt > output.txt
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How to create a CPU spike with a bash command
...st a designated amount of time and then stop. I'm hoping there's some trick in bash. I'm thinking some sort of infinite loop.
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How to make return key on iPhone make keyboard disappear?
...wo UITextFields (e.g. username and password) but I cannot get rid of the keyboard when pressing the return key on the keyboard. How can I do this?
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Can I record/play macros in Visual Studio 2012/2013/2015/2017/2019?
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Xavier PoinasXavier Poinas
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How do I log a Python error with debug information?
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logger.exception will output a stack trace alongside the error message.
For example:
import logging
try:
1/0
except ZeroDivisionError:
logging.exception("message")
Output:
ERROR:root:message
Traceback (most recent call last):
File "<stdin>", l...
Are list-comprehensions and functional functions faster than “for loops”?
In terms of performance in Python, is a list-comprehension, or functions like map() , filter() and reduce() faster than a for loop? Why, technically, they run in a C speed , while the for loop runs in the python virtual machine speed ?.
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How to find unused/dead code in java projects [closed]
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I would instrument the running system to keep logs of code usage, and then start inspecting code that is not used for months or years.
For example if you are interested in unused classes, all classes could be instrumented to log when instances are created. And then...
Concat all strings inside a List using LINQ
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By using LINQ, this should work;
string delimiter = ",";
List<string> items = new List<string>() { "foo", "boo", "john", "doe" };
Console.WriteLine(items.Aggregate((i, j) => i + delimiter + j));
class description:
public class Foo
{
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How to manually send HTTP POST requests from Firefox or Chrome browser?
I want to test some URLs on a web application I'm working on. For that I would like to manually create HTTP POST requests (meaning I can add whatever parameters I like).
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