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`elif` in list comprehension conditionals
Can we use elif in list comprehension?
6 Answers
6
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How to represent multiple conditions in a shell if statement?
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Classic technique (escape metacharacters):
if [ \( "$g" -eq 1 -a "$c" = "123" \) -o \( "$g" -eq 2 -a "$c" = "456" \) ]
then echo abc
else echo efg
fi
I've enclosed the references to $g in double quotes; that's good practice, in general. Strictly, the parentheses ar...
Check existence of input argument in a Bash shell script
...
It is:
if [ $# -eq 0 ]
then
echo "No arguments supplied"
fi
The $# variable will tell you the number of input arguments the script was passed.
Or you can check if an argument is an empty string or not like:
if [ -z "$1" ]
t...
One-line list comprehension: if-else variants
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x if y else z is the syntax for the expression you're returning for each element. Thus you need:
[ x if x%2 else x*100 for x in range(1, 10) ]
The confusion arises from the fact you're using a filter in the first example, bu...
Fixing JavaScript Array functions in Internet Explorer (indexOf, forEach, etc.) [closed]
... to put this in writing. The wiki as a whole is CC Attribution-ShareAlike, if that's an acceptable licence (though CC isn't designed for code as such).
js-methods looks OK in general, but is not as standards-compliant around the edges of how the functions are supposed to be (eg. undefined list item...
How can I delete a query string parameter in JavaScript?
... parameter ‘bar’ would match:
?a=b&foobar=c
Also, it would fail if parameter contained any characters that are special in RegExp, such as ‘.’. And it's not a global regex, so it would only remove one instance of the parameter.
I wouldn't use a simple RegExp for this, I'd parse the pa...
Calculate difference in keys contained in two Python dictionaries
...e I have two Python dictionaries - dictA and dictB . I need to find out if there are any keys which are present in dictB but not in dictA . What is the fastest way to go about it?
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SQLite - UPSERT *not* INSERT or REPLACE
...ddition to INSERT that causes the INSERT to behave as an UPDATE or a no-op if the INSERT would violate a uniqueness constraint. UPSERT is not standard SQL. UPSERT in SQLite follows the syntax established by PostgreSQL.
GOOD but tendous: This will update 2 of the columns.
When ID=1 exists, the NA...
How to dump a table to console?
...on: how do I go about installing an extension like pl.pretty? It's be nice if I could just do something like a gem install without futzing with unrolling tar balls and finding the ideal spot on my HD to situate things. Is there a quick/painless "do-it-this-way"?
– Cliff
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How can I remove a specific item from an array?
...ay = [2, 5, 9];
console.log(array);
const index = array.indexOf(5);
if (index > -1) {
array.splice(index, 1);
}
// array = [2, 9]
console.log(array);
The second parameter of splice is the number of elements to remove. Note that splice modifies the array in place and returns...