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How to tell if a string is not defined in a Bash shell script
...To distinguish whether VAR is set but empty or not set, you can use:
if [ -z "${VAR+xxx}" ]; then echo VAR is not set at all; fi
if [ -z "$VAR" ] && [ "${VAR+xxx}" = "xxx" ]; then echo VAR is set but empty; fi
You probably can combine the two tests on the second line into one with:
if [ -z ...
How to create a new object instance from a Type
...
Jay
14433 silver badges1616 bronze badges
answered Aug 3 '08 at 16:35
Karl SeguinKarl Seguin
19.9k55 gold badg...
CSS z-index paradox flower
I would like to create a paradoxical effect via the z-index CSS property.
6 Answers
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How do I translate an ISO 8601 datetime string into a Python datetime object? [duplicate]
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I prefer using the dateutil library for timezone handling and generally solid date parsing. If you were to get an ISO 8601 string like: 2010-05-08T23:41:54.000Z you'd have a fun time parsing that with strptime, especially if you didn't know up front whether or not the ...
What does -z mean in Bash? [duplicate]
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-z string True if the string is null (an empty string)
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Evenly distributing n points on a sphere
... you, hopefully you can use that now.
(in other words, k is an array of size N that is defined before the code fragment starts, and which contains a list of the points).
Alternatively, building on the other answer here (and using Python):
> cat ll.py
from math import asin
nx = 4; ny = 5
for x ...
Scala constructor overload?
...ructor is the sole point of entry to the class.
class Foo(x: Int, y: Int, z: String) {
// default y parameter to 0
def this(x: Int, z: String) = this(x, 0, z)
// default x & y parameters to 0
// calls previous auxiliary constructor which calls the primary constructor
def this...
Is it possible to apply CSS to half of a character?
...w on GitHub as a Plugin!
Feel free to fork and improve.
Demo | Download Zip | Half-Style.com (Redirects to GitHub)
Pure CSS for a Single Character
JavaScript used for automation across text or multiple characters
Preserves Text Accessibility for screen readers for the blind or visually
impair...
Omit rows containing specific column of NA
... a function thusly:
DF <- data.frame(x = c(1, 2, 3), y = c(0, 10, NA), z=c(NA, 33, 22))
completeFun <- function(data, desiredCols) {
completeVec <- complete.cases(data[, desiredCols])
return(data[completeVec, ])
}
completeFun(DF, "y")
# x y z
# 1 1 0 NA
# 2 2 10 33
completeFun(...
Link to add to Google calendar
...r/render?action=TEMPLATE&text=Your+Event+Name&dates=20140127T224000Z/20140320T221500Z&details=For+details,+link+here:+http://www.example.com&location=Waldorf+Astoria,+301+Park+Ave+,+New+York,+NY+10022&sf=true&output=xml
Note the key query parameters:
text
dates
details
loca...