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Replace None with NaN in pandas dataframe
...beware when you run df.replace([None], np.nan, inplace=True), this changed all datetime objects with missing data to object dtypes. So now you may have broken queries unless you change them back to datetime which can be taxing depending on the size of your data.
– Doubledown
...
Two-way encryption: I need to store passwords that can be retrieved
...
Personally, I would use mcrypt like others posted. But there is much more to note...
How do I encrypt and decrypt a password in PHP?
See below for a strong class that takes care of everything for you:
What is the safest algorit...
What is the difference between const int*, const int * const, and int const *?
...= int const *
const int * const == int const * const
If you want to go really crazy you can do things like this:
int ** - pointer to pointer to int
int ** const - a const pointer to a pointer to an int
int * const * - a pointer to a const pointer to an int
int const ** - a pointer to a pointer t...
What's wrong with overridable method calls in constructors?
...ohibit it:
There are a few more restrictions that a class must obey to allow inheritance. Constructors must not invoke overridable methods, directly or indirectly. If you violate this rule, program failure will result. The superclass constructor runs before the subclass constructor, so the overr...
Benefit of using Parcelable instead of serializing object
...our objects.
Also realize that Android provides two mechanisms that allow you to pass
data to another
process. The first is to pass a bundle to an activity using an intent,
and the second is to pass a
Parcelable to a service. These two mechanisms are not interchangeable and
...
Maintain aspect ratio of div but fill screen width and height in CSS?
...t units vw and vh (viewport width / viewport height)
FIDDLE
Resize vertically and horizontally and you'll see that the element will always fill the maximum viewport size without breaking the ratio and without scrollbars!
(PURE) CSS
div
{
width: 100vw;
height: 56.25vw; /* height:width ra...
How do I measure execution time of a command on the Windows command line?
... keyname.
-a specifies that timeit should display average of all timings
for the specified key.
-i specifies to ignore non-zero return codes from program
-d specifies to show detail for average
-s specifies to suppress system w...
Choosing a stand-alone full-text search server: Sphinx or SOLR? [closed]
...ake patches to my answer :-)
Similarities:
Both Solr and Sphinx satisfy all of your requirements. They're fast and designed to index and search large bodies of data efficiently.
Both have a long list of high-traffic sites using them (Solr, Sphinx)
Both offer commercial support. (Solr, Sphinx)
Bot...
Equivalent to 'app.config' for a library (DLL)
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You can have separate configuration file, but you'll have to read it "manually", the ConfigurationManager.AppSettings["key"] will read only the config of the running assembly.
Assuming you're using Visual Studio as your IDE, you can right click the desired project → Add → New item → Applicat...
Should JAVA_HOME point to JDK or JRE?
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Is it possible to validate pro-grammatically whether the Java path is set as JRE or JDK?
– Dinesh Kumar P
Mar 2 '18 at 11:22
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