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List comprehension with if statement
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You got the order wrong. The if should be after the for (unless it is in an if-else ternary operator)
[y for y in a if y not in b]
This would work however:
[y if y not in b else other_value for y in a]
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Why '&&' and not '&'?
...at the evaluation is canceled as soon as the result is clear.
Example:
if(CanExecute() && CanSave())
{
}
If CanExecute returns false, the complete expression will be false, regardless of the return value of CanSave. Because of this, CanSave is not executed.
This is very handy in the f...
Check if the number is integer
... was surprised to learn that R doesn't come with a handy function to check if the number is integer.
12 Answers
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Shortest distance between a point and a line segment
... const float l2 = length_squared(v, w); // i.e. |w-v|^2 - avoid a sqrt
if (l2 == 0.0) return distance(p, v); // v == w case
// Consider the line extending the segment, parameterized as v + t (w - v).
// We find projection of point p onto the line.
// It falls where t = [(p-v) . (w-v)] /...
How to get the caret column (not pixels) position in a textarea, in characters, from the start?
..., so you will have to do something like this:
function getCaret(node) {
if (node.selectionStart) {
return node.selectionStart;
} else if (!document.selection) {
return 0;
}
var c = "\001",
sel = document.selection.createRange(),
dul = sel.duplicate(),
len = 0;
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Jinja2 template variable if None Object set a default value
How to make a variable in jijna2 default to "" if object is None instead of doing something like this?
9 Answers
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How can I check if a key exists in a dictionary? [duplicate]
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if key in array:
# do something
Associative arrays are called dictionaries in Python and you can learn more about them in the stdtypes documentation.
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How to convert number to words in java
...= {
"",
" ten",
" twenty",
" thirty",
" forty",
" fifty",
" sixty",
" seventy",
" eighty",
" ninety"
};
private static final String[] numNames = {
"",
" one",
" two",
" three",
" four",
" five",
" six",
" seven",
" eigh...
Best way to “negate” an instanceof
I was thinking if there exists a better/nicer way to negate an instanceof in Java.
Actually, I'm doing something like:
9 ...
Whether a variable is undefined [duplicate]
How do I find if a variable is undefined?
5 Answers
5
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