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How to drop rows of Pandas DataFrame whose value in a certain column is NaN
...ta, including dropna(), is built into pandas explicitly. Aside from potentially improved performance over doing it manually, these functions also come with a variety of options which may be useful.
In [24]: df = pd.DataFrame(np.random.randn(10,3))
In [25]: df.iloc[::2,0] = np.nan; df.iloc[::4,1] ...
What does the 'static' keyword do in a class?
...llion instances of the class or you don't create any. It will be shared by all instances.
Since static methods also do not belong to a specific instance, they can't refer to instance members. In the example given, main does not know which instance of the Hello class (and therefore which instance of...
What REALLY happens when you don't free after malloc?
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Just about every modern operating system will recover all the allocated memory space after a program exits. The only exception I can think of might be something like Palm OS where the program's static storage and runtime memory are pretty much the same thing, so not freeing mig...
What can you use Python generator functions for?
...in them. I want to know what types of problems that these functions are really good at solving.
16 Answers
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Concat all strings inside a List using LINQ
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I am all for LINQ solutions but this is more efficient than LINQ and the Aggregate() method.
– andleer
Feb 20 '09 at 18:29
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What is the difference between persist() and merge() in JPA and Hibernate?
...these
other entities are annotated with the
cascade=PERSIST or cascade=ALL
annotation element value or specified
with the equivalent XML descriptor
element.
If X is a removed entity,
it becomes managed.
If X is a
detached object, the
EntityExistsException may be thrown
when the...
What are the aspect ratios for all Android phone and tablet devices?
I'm looking for a list of all screen aspect ratios for popular Android based Phones and Tablets.
5 Answers
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Get the subdomain from a URL
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Anyone have any great ideas besides
storing a list of all TLDs?
No, because each TLD differs on what counts as a subdomain, second level domain, etc.
Keep in mind that there are top level domains, second level domains, and subdomains. Technically speaking, everything except ...
Code block in numbered list (Wiki syntax)
...two
It is not perfect, because you end up with a more indent but it does allow one to use the wiki syntax for correctly formatted pre blocks over multiple lines.
As previously mentioned, the other proper way would be to use HTML mark up.
<ol>
<li>one</li>
<li>two</li&g...
Twitter Bootstrap Customization Best Practices [closed]
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theme.less
variables.less
/Bootstrap
...
Update all the references in theme.less to point to bootstrap sub-directory. Ensure that your variables.less is referenced from the parent and not the bootstrap directory like so:
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// CSS Reset
@import "bootstrap/reset.less";
/...