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Regex, every non-alphanumeric character except white space or colon
... - matches all the letters
^ - negates them all - so you get - non numeric chars, non spaces and non colons
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Difference between HashMap, LinkedHashMap and TreeMap
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private TreeMap<String ,Integer> mySection2 = new TreeMap<>(); mySection2.put("abc1", 2); mySection2.put("abc2",5); mySection2.put("abc3",3); ...
How to drop rows of Pandas DataFrame whose value in a certain column is NaN
...ilippSchwarz This error occurs if the column (EPS in the example) contains strings or other types that cannot be digested by np.isfinite(). I recommend to use pandas.notnull() that will handle this more generously.
– normanius
Apr 5 '18 at 10:02
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Why should I avoid using Properties in C#?
...ly-typed system, to avoid what Fowler calls Syntactic Noise. We don't want extra parentheses, extra get/set warts, or extra method signatures - not if we can avoid them without any loss of clarity.
Say whatever you like, but foo.Bar.Baz = quux.Answers[42] is always going to be a lot easier to read ...
Bash script to receive and repass quoted parameters
...# $4= "ddd ddd"
"$*" - quoted-dollar-star smashes the args into a single string (~1% of the time you actually want this behavior, eg in a conditional: if [[ -z "$*" ]]; then ...):
./quoted-dollar-star.sh aaa '' "'cc cc'" '"ddd ddd"'
# $1= aaa 'cc cc' "ddd ddd"
# $2=
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Return 0 if field is null in MySQL
...) returns expr1; otherwise it returns expr2. IFNULL() returns a numeric or string value, depending on the context in which it is used.
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How does IPython's magic %paste work?
...est_mode which allows you to copy paste example and test snippets from doc strings. This is also useful to execute interactive python session output that you could find in documentation and online forums, without having to first strip out the prompt strings.
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Disabling swap files creation in vim
...ing which is a large part of vim use for a lot of people, it seems like an extra bookeeping job better left out. I personally prefer for all jobs to just have no swaps or other auto-backups. If I really need to develop something, I'd rather have a more high level framework to protect me, preferably ...
bash assign default value
...riable without needing to reassign
# colons suppress attempting to run the string
unset EGGS
: ${EGGS=spam}
echo 1 $EGGS # 1 spam
unset EGGS
: ${EGGS:=spam}
echo 2 $EGGS # 2 spam
EGGS=
: ${EGGS=spam}
echo 3 $EGGS # 3 (set, but blank -> leaves alone)
EGGS=
: ${EGGS:=spam}
echo ...
Using union and order by clause in mysql
...organize.
But this way has the advantage of being fast, not introducing extra variables, and making it easy to separate out each query including the sort. The ability to add a limit is simply an extra bonus.
And of course feel free to turn the union all into a union and add a sort for the whole...