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Adding 'serial' to existing column in Postgres
I have a small table (~30 rows) in my Postgres 9.0 database with an integer ID field (the primary key) which currently contains unique sequential integers starting at 1, but which was not created using the 'serial' keyword.
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How to comment out a block of code in Python [duplicate]
...+4.
Don't use triple-quotes; as you discovered, this is for documentation strings not block comments, although it has a similar effect. If you're just commenting things out temporarily, this is fine as a temporary measure.
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Save Javascript objects in sessionStorage
...orage allows to save key/value pairs in a web browser. The value must be a string, and save js objects is not trivial.
9 An...
Android SDK Manager Not Installing Components
Not sure what I'm doing wrong here. I installed the Android SDK Manager, and am now trying to install a platform like the Android Dev website suggests. Once I clicked install I got an error stating that the Manager could not create a temp folder within the Android directory. So I created it. Now I'm...
cv2.imshow command doesn't work properly in opencv-python
... only works with waitKey():
import cv2
img = cv2.imread('C:/Python27/03323_HD.jpg')
cv2.imshow('ImageWindow', img)
cv2.waitKey()
(The whole message-loop necessary for updating the window is hidden in there.)
share
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rsync error: failed to set times on “/foo/bar”: Operation not permitted
...rom rsync and the initial things I'm finding from web searches (as well as all the usual chmod'ing) are not solving it:
9 A...
Is it possible to have different Git configuration for different projects?
.gitconfig is usually stored in the user.home directory.
12 Answers
12
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Pandas count(distinct) equivalent
...if I have multiple columns that I want to be unique together, like in .drop_duplicates(subset=['col1','col2'])?
– ErnestScribbler
Oct 2 '17 at 8:10
4
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Check if inputs are empty using jQuery
...And you don't necessarily need .length or see if it's >0 since an empty string evaluates to false anyway but if you'd like to for readability purposes:
$('#apply-form input').blur(function()
{
if( $(this).val().length === 0 ) {
$(this).parents('p').addClass('warning');
}
});
If...
Xcode suddenly stopped running project on hardware: “Could not launch xxx.app: .. No such file..” [c
...tarted directly after I deleted it from the device and attempted to re-install by rerunning it in Xcode (something I've done hundreds of times before).
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