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What is the difference between join and merge in Pandas?
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I always use join on indices:
import pandas as pd
left = pd.DataFrame({'key': ['foo', 'bar'], 'val': [1, 2]}).set_index('key')
right = pd.DataFrame({'key': ['foo', 'bar'], 'val': [4, 5]}).set_index('key')
left.join(right, lsuffix='_l', rsuffix='_r')
val_l ...
PostgreSQL function for last inserted ID
...an id column created with the SERIAL pseudo-type. To avoid relying on this and to feel more clean, you can use instead pg_get_serial_sequence:
INSERT INTO persons (lastname,firstname) VALUES ('Smith', 'John');
SELECT currval(pg_get_serial_sequence('persons','id'));
Caveat: currval() only work...
jquery.validate.unobtrusive not working with dynamic injected elements
... with the latest MVC RC? or they just fixed that?
– xandy
Jan 24 '11 at 10:03
1
When using the co...
Make HTML5 video poster be same size as video itself
...ieve this (example); however, to have a background stretched to the height and the width of a video, you'll have to use an absolutely positioned <img> tag (example).
It is also possible to set background-size to 100% 100% in browsers that support background-size (example).
Update
A better wa...
How to select multiple files with ?
...a On the 20th of October of 2009 most browsers didn't support that feature and Niavlys already showed the html5 solution 2 years ago.
– ZippyV
Jul 5 '13 at 23:40
3
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Clustered vs Non-Clustered
My lower level knowledge of SQL (Server 2008) is limited, and is now being challanged by our DBAs. Let me explain (I have mentioned obvious statements in the hope that I am right, but if you see something wrong, please tell me) the scenario:
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Android: How can I get the current foreground activity (from a service)?
Is there a native android way to get a reference to the currently running Activity from a service?
12 Answers
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How can I configure NetBeans to insert tabs instead of a bunch of spaces?
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Go to Tools-> Options-> Editor-> Formatting and uncheck Expand tabs to spaces:
Ensure you also pick coherent values for "Number of Spaces per indent" and "Tab Size".
Additionally, you can check all the items in the Language combo and make sure they all use the ge...
What is the best way to filter a Java Collection?
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Java 8 (2014) solves this problem using streams and lambdas in one line of code:
List<Person> beerDrinkers = persons.stream()
.filter(p -> p.getAge() > 16).collect(Collectors.toList());
Here's a tutorial.
Use Collection#removeIf to modify the collection...
NoSql vs Relational database
...nal. For those situations, NoSQL can be helpful.
With that said, NoSQL stands for "Not Only SQL". It's not intended to knock SQL or supplant it.
SQL has several very big advantages:
Strong mathematical basis.
Declarative syntax.
A well-known language in Structured Query Language (SQL).
Th...