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How can I obtain the element-wise logical NOT of a pandas Series?
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Wierd, I actually tested the tilde as it was mentioned in the documentation, but it didn't perform the same as np.invert :S
– root
Apr 14 '13 at 13:11
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How to delete migration files in Rails 3
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I usually:
Perform a rake db:migrate VERSION=XXX on all environments, to the version before the one I want to delete.
Delete the migration file manually.
If there are pending migrations (i.e., the migration I removed was not the...
There is already an open DataReader associated with this Command which must be closed first
...en iterating over the results of some query.
This can be easily solved by allowing MARS in your connection string. Add MultipleActiveResultSets=true to the provider part of your connection string (where Data Source, Initial Catalog, etc. are specified).
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How do I get the MAX row with a GROUP BY in LINQ query?
... (s => s.uid, tv => tv.uid, asdf => asdf.uid). Linq will automatically recognize it as selecting over elements of type Serial.
– Michael
Mar 17 '11 at 17:03
add a com...
what is reverse() in Django
...!-- django <= 1.4 -->
<a href="{% url url_name %}">link which calls some_view</a>
<!-- django >= 1.5 or with {% load url from future %} in your template -->
<a href="{% url 'url_name' %}">link which calls some_view</a>
This will be rendered as:
<a href="...
If vs. Switch Speed
Switch statements are typically faster than equivalent if-else-if statements (as e.g. descibed in this article ) due to compiler optimizations.
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The Concept of 'Hold space' and 'Pattern space' in sed
... line. So what happens is this:
first line is read and inserted automatically into the pattern space
on the first line, first command is not executed; h copies the first line into the hold space.
now the second line replaces whatever was in the pattern space
on the second line, first we execute G,...
How to get a Docker container's IP address from the host
...n. Maybe provide two examples clearly labelled Linux and Windows. I literally just typed the example, checked the docs which also uses single quotes and then Googled the error. I'm sure I'm not alone.
– Wyck
Apr 15 '19 at 18:42
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PHP session lost after redirect
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First, carry out these usual checks:
Make sure session_start(); is called before any sessions are being called. So a safe bet would be to put it at the beginning of your page, immediately after the opening <?php declaration before anything else. Also ensure there are no whitespaces/tabs be...
How to create a GUID/UUID using iOS
...tring = CFUUIDCreateString(NULL, theUUID);
CFRelease(theUUID);
return (__bridge NSString *)string;
}
EDIT: Jan, 29 2014:
If you're targeting iOS 6 or later, you can now use the much simpler method:
NSString *UUID = [[NSUUID UUID] UUIDString];
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