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Python: What OS am I running on?
...ion of Darwin that comes with Catalina 10.15.2: en.wikipedia.org/wiki/MacOS_Catalina#Release_history
– philshem
Aug 21 at 13:28
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How do I remove a property from a JavaScript object?
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Another alternative is to use the Underscore.js library.
Note that _.pick() and _.omit() both return a copy of the object and don't directly modify the original object. Assigning the result to the original object should do the trick (not shown).
Reference: link _.pick(object, *keys)
Return...
How many socket connections can a web server handle?
...ic on a single Unix flavoured OS machine - https://blog.whatsapp.com/index.php/2012/01/1-million-is-so-2011/.
And finally, this one, http://highscalability.com/blog/2013/5/13/the-secret-to-10-million-concurrent-connections-the-kernel-i.html, goes into a lot of detail, exploring how even 10 million c...
How to count the number of set bits in a 32-bit integer?
... may need to adjust it to work for a particular language (e.g. using uint32_t for C++ and >>> in Java):
int numberOfSetBits(uint32_t i)
{
// Java: use int, and use >>> instead of >>
// C or C++: use uint32_t
i = i - ((i >> 1) & 0x55555555);
i = (...
JavaScript hashmap equivalent
...ache the hash value in the object itself (for example, in a property named __hash).
A hash function which does this is and works for both primitive values and objects is:
function hash(value) {
return (typeof value) + ' ' + (value instanceof Object ?
(value.__hash || (value.__hash = ++ar...
How do you get the logical xor of two variables in Python?
...nt to bitwise xor when the domain is restricted to 0 and 1.
So the logical_xor function would be implemented like:
def logical_xor(str1, str2):
return bool(str1) ^ bool(str2)
Credit to Nick Coghlan on the Python-3000 mailing list.
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How to concatenate properties from multiple JavaScript objects
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Underscore has few methods to do this;
1. _.extend(destination, *sources)
Copy all of the properties in the source objects over to the destination object, and return the destination object.
_.extend(a, _.extend(b, c));
=> {"one" : 1, "two" : 2, "three" : 3, "fo...
Open link in new tab or window [duplicate]
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You should add the target="_blank" and rel="noopener noreferrer" in the anchor tag.
For example:
<a target="_blank" rel="noopener noreferrer" href="http://your_url_here.html">Link</a>
Adding rel="noopener noreferrer" is not mandatory, b...
How do I format a string using a dictionary in python-3.x?
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Python 3.2 introduced format_map. Similar to str.format(**mapping), except that mapping is used directly and not copied to a dict. This is useful if for example mapping is a dict subclass
– diapir
Jan 17 '15 at 14:...
check if variable is dataframe
...rame
Yes: isinstance(x, pd.DataFrame)
And don't even think about
if obj.__class__.__name__ = 'DataFrame':
expect_problems_some_day()
isinstance handles inheritance (see What are the differences between type() and isinstance()?). For example, it will tell you if a variable is a string (eithe...