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Can you grab or delete between parentheses in vi/vim?
... | |
\_______\___---> Cursor range
assuming that your cursor is inside the above mentioned cursor range, you can issue the following commands :
di( --> Deletes '5.0/9.0'
ci( --> Substitutes '5.0/9.0'
yi( --> Y...
Understanding scala enumerations
...s. It is useful, because after you import it elsewhere with import WeekDay._, you can use that type, e.g.:
def isWorkingDay(d: WeekDay) = ! (d == Sat || d == Sun)
Instead, a minimal version would just be:
object WeekDay extends Enumeration {
val Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value
}
an...
javac : command not found
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yes, i am sure. just look at the java-1.6.0-openjdk.x86_64 package information (scroll to the "Files" section) and see that there is no javac in that package. and then look at the OpenJDK Development Environment package.
– ax.
Mar 23 '11 at ...
Rails Root directory path?
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which returns a Pathname object. If you want a string you have to add .to_s. If you want another path in your Rails app, you can use join like this:
Rails.root.join('app', 'assets', 'images', 'logo.png')
In Rails 2 you can use the RAILS_ROOT constant, which is a string.
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Is there a way to access an iteration-counter in Java's for-each loop?
...t variant of for iterates over) even have an index, or even have a defined order (some collections may change the order when you add or remove elements).
See for example, the following code:
import java.util.*;
public class TestApp {
public static void AddAndDump(AbstractSet<String> set, ...
Can Python test the membership of multiple values in a list?
...o sets can sometimes be incredibly wasteful, slowing programs down by many orders of magnitude.
Here are a few benchmarks for illustration. The biggest difference comes when both container and items are relatively small. In that case, the subset approach is about an order of magnitude faster:
>...
how to create a file name with the current date & time in python?
... human readable.
from datetime import datetime
datetime.now().strftime("%Y_%m_%d-%I_%M_%S_%p")
'2020_08_12-03_29_22_AM'
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How to turn on/off ReactJS 'development mode'?
...tely the magic comes down to React embedding references to process.env.NODE_ENV throughout the codebase; these act like a feature toggle.
if (process.env.NODE_ENV !== "production")
// do propType checks
The above is the most common pattern, and other libraries follow it as well. So to "disable" t...
What Makes a Method Thread-safe? What are the rules?
...e a complete knowledge of the threading behaviour of the entire program in order to ensure its safety.
Again, look at my example: every method is trivial. It is the way that the methods interact with each other at a "global" level that makes the program deadlock. You can't look at every method and...
Days between two dates? [duplicate]
...est for calendar checks.
from datetime import timedelta, datetime
def cal_days_diff(a,b):
A = a.replace(hour = 0, minute = 0, second = 0, microsecond = 0)
B = b.replace(hour = 0, minute = 0, second = 0, microsecond = 0)
return (A - B).days
if __name__ == '__main__':
x = datetime...