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check if variable is dataframe
when my function f is called with a variable I want to check if var is a pandas dataframe:
2 Answers
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Should I use multiplication or division?
...5 end'
real 0m7.997s
user 0m7.516s
sys 0m0.036s
=> no real difference
LuaJIT:
time luajit -O -e 'for i=1,1e8 do t=12341234234.234 / 2.0 end'
real 0m1.921s
user 0m1.668s
sys 0m0.004s
time luajit -O -e 'for i=1,1e8 do t=12341234234.234 * 0.5 end'
real 0m1.843s
user 0m...
Given a class, see if instance has method (Ruby)
I know in Ruby that I can use respond_to? to check if an object has a certain method.
12 Answers
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Safely casting long to int in Java
What's the most idiomatic way in Java to verify that a cast from long to int does not lose any information?
10 Answers
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How to get the insert ID in JDBC?
...
If it is an auto generated key, then you can use Statement#getGeneratedKeys() for this. You need to call it on the same Statement as the one being used for the INSERT. You first need to create the statement using Statement.RE...
nil detection in Go
... // not nil
or
var config *Config // nil
Then you'll be able to check if
if config == nil {
// then
}
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Print a file, skipping the first X lines, in Bash [duplicate]
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$ tail great-big-file.log
< Last 10 lines of great-big-file.log >
If you really need to SKIP a particular number of "first" lines, use
$ tail -n +<N+1> <filename>
< filename, excluding first N lines. >
That is, if you want to skip N lines, you start printing line N+1. E...
How can I click a button behind a transparent UIView?
...rn false when the point isn't within an eligible child view, like this:
Swift:
class PassThroughView: UIView {
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
for subview in subviews {
if !subview.isHidden && subview.isUserInteractionEn...
What is the volatile keyword useful for?
...ome code continues a loop. The loop tests the volatile value and continues if it is true. The condition can be set to false by calling a "stop" method. The loop sees false and terminates when it tests the value after the stop method completes execution.
The book "Java Concurrency in Practice," whic...
How to remove a column from an existing table?
...y additional table changes but generally speaking this is not so trivial.
If this column is referenced by other tables then you need to figure out what to do with other tables/columns. One option is to remove foreign keys and keep referenced data in other tables.
Another option is to find all refe...