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How to filter Pandas dataframe using 'in' and 'not in' like in SQL
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If you're actually dealing with 1-dimensional arrays (like in you're example) then on you're first line use a Series instead of a DataFrame, like @DSM used: df = pd.Series({'countries':['US','UK','Germany','China']})
–...
JOIN queries vs multiple queries
...ase. It depends on a lot of things. Jeff Atwood (founder of this site) actually wrote about this. For the most part, though, if you have the right indexes and you properly do your JOINs it is usually going to be faster to do 1 trip than several.
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AttributeError: 'module' object has no attribute 'tests'
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I finally figured it out working on another problem. The problem was that my test couldn't find an import.
It looks like you get the above error if your test fails to import. This makes sense because the test suite can't import ...
How to preview git-pull without doing fetch?
...EAD...origin/master (three dots not two) to show a single diff.
There normally isn't any need to undo a fetch, because doing a fetch only updates the remote branches and none of your branches. If you're not prepared to do a pull and merge in all the remote commits, you can use git cherry-pick to ac...
Correct way to use StringBuilder in SQL
... of using StringBuilder, i.e reducing memory. Is it achieved?
No, not at all. That code is not using StringBuilder correctly. (I think you've misquoted it, though; surely there aren't quotes around id2 and table?)
Note that the aim (usually) is to reduce memory churn rather than total memory used...
Which “href” value should I use for JavaScript links, “#” or “javascript:void(0)”?
...evelopers inevitably leads to some using the return value of the function called like this:
function doSomething() {
//Some code
return false;
}
But then they forget to use return doSomething() in the onclick and just use doSomething().
A second reason for avoiding # is that the final re...
How to fix “Referenced assembly does not have a strong name” error?
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To avoid this error you could either:
Load the assembly dynamically, or
Sign the third-party assembly.
You will find instructions on signing third-party assemblies in .NET-fu: Signing an Unsigned Assembly (Without Delay Signing).
Signing Third-Party Assemblies
The basic principle t...
Is there a way to get rid of accents and convert a whole string to regular letters?
...f accents and making those letters regular apart from using String.replaceAll() method and replacing letters one by one?
Example:
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How can I deploy/push only a subdirectory of my git repo to Heroku?
... Yep, but subtree is still (as of 1.8.0.2) not included via the git installer. Luckily installing from source is quick and straightforward, this page worked for me on mac.
– dribnet
Dec 29 '12 at 22:19
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How to add a primary key to a MySQL table?
... Column
If you want to add a primary key constraint to an existing column all of the previously listed syntax will fail.
To add a primary key constraint to an existing column use the form:
ALTER TABLE `goods`
MODIFY COLUMN `id` INT(10) UNSIGNED PRIMARY KEY AUTO_INCREMENT;
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