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Combine two or more columns in a dataframe into a new column with a new name
...g paste()? For above example, x column should have data as 2-aa, then 3-bb and 5-cc.
– Chetan Arvind Patil
Oct 6 '17 at 2:28
...
How can I add new array elements at the beginning of an array in Javascript?
...push - add an element to the beginning/end of an array
shift/pop - remove and return the first/last element of an array
A simple diagram...
unshift -> array <- push
shift <- array -> pop
and chart:
add remove start end
push X X
pop ...
Fix warning “Capturing [an object] strongly in this block is likely to lead to a retain cycle” in AR
...
Replying to myself:
My understanding of the documentation says that using keyword block and setting the variable to nil after using it inside the block should be ok, but it still shows the warning.
__block ASIHTTPRequest *request = [[ASIHTTPRequest alloc...
How to scroll to top of page with JavaScript/jQuery?
... = 'manual';
}
// This is needed if the user scrolls down during page load and you want to make sure the page is scrolled to the top once it's fully loaded. This has Cross-browser support.
window.scrollTo(0,0);
history.scrollRestoration Browser support:
Chrome: supported (since 46)
Firefox: sup...
Pickle incompatibility of numpy arrays between Python 2 and 3
...oding = 'latin1'
p = u.load()
print(p)
Unpickling it in Python 2 and then repickling it is only going to create the same problem again, so you need to save it in another format.
share
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im...
How to find the Git commit that introduced a string in any branch?
...xed string whatever. The --all parameter means to start from every branch and --source means to show which of those branches led to finding that commit. It's often useful to add -p to show the patches that each of those commits would introduce as well.
Versions of git since 1.7.4 also have a simi...
PHP - Move a file into a different folder on the server
...ink function in PHP but have since been told that this can be quite risky and a security issue. (Previous code below:)
8 A...
Copying files from one directory to another in Java
...directory, dir, with text files. I iterate over the first 20 files in dir, and want to copy them to another directory in the dir directory, which I have created right before the iteration.
In the code, I want to copy the review (which represents the ith text file or review) to trainingDir . How c...
Is there a way to auto expand objects in Chrome Dev Tools?
EVERY SINGLE TIME I view an object in the console I am going to want to expand it, so it gets tiresome to have to click the arrow to do this EVERY SINGLE TIME :) Is there a shortcut or setting to have this done automatically?
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How to swap two variables in JavaScript
...
Here's a one-liner to swap the values of two variables.
Given variables a and b:
b = [a, a = b][0];
Demonstration below:
var a=1,
b=2,
output=document.getElementById('output');
output.innerHTML="<p>Original: "+a+", "+b+"</p>";
b = [a, a = b][0];
output.innerHT...