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Any difference between First Class Function and High Order Function
... functions
Values in a language that are handled uniformly throughout are called "first class". They may be stored in data structures, passed as arguments, or used in control structures.
Languages which support values with function types, and treat them the same as non-function values, can be said...
How do I parse JSON with Objective-C?
...NSClassFromString(@"NSJSONSerialization"))
{
NSError *error = nil;
id object = [NSJSONSerialization
JSONObjectWithData:returnedData
options:0
error:&error];
if(error) { /* JSON was malformed, act appropriately here */...
Equivalent of varchar(max) in MySQL?
...f your column is null/not null this gets stored as one bit in a byte/bytes called the null mask, 1 bit per column that is nullable.
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Update or Insert (multiple rows and columns) from subquery in PostgreSQL
... as col2, t3.foobar as col3
FROM table2 t2 INNER JOIN table3 t3 ON t2.id = t3.t2_id
WHERE t2.created_at > '2016-01-01'
) AS subquery
WHERE table1.id = subquery.col1;
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How to filter Pandas dataframe using 'in' and 'not in' like in SQL
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Series.isin accepts various types as inputs. The following are all valid ways of getting what you want:
df['countries'].isin(c1)
0 False
1 True
2 False
3 False
4 True
Name: countries, dtype: bool
# `in` operation
df[df['countries'].isin(c1)]
countries
1 UK
4 Ch...
Should __init__() call the parent class's __init__()?
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In Python, calling the super-class' __init__ is optional. If you call it, it is then also optional whether to use the super identifier, or whether to explicitly name the super class:
object.__init__(self)
In case of object, calling t...
What does iota of std::iota stand for?
...he Roman I, i; the smallest letter of the Greek alphabet” (smallest physically, not alphabetically, I presume), and also means “The least, or a very small, particle or quantity”. The OED's earliest known usage of this meaning is from Clavis mystica by Daniel Featley in 1636:
Shall we lose,...
Python `if x is not None` or `if not x is None`?
... of the if not x is None version to be more clear, but Google's style guide and PEP-8 both use if x is not None . Is there any minor performance difference (I'm assuming not), and is there any case where one really doesn't fit (making the other a clear winner for my convention)?*
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Android activity life cycle - what are all these methods for?
...so many similar sounding methods ( onCreate() , onStart() , onResume() ) called during initialization, and so many others ( onPause() , onStop() , onDestroy() ) called at the end?
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PostgreSQL Connection URL
... postgresql://localhost/mydb?user=other&password=secret did the trick
– Karuhanga
Oct 29 '18 at 14:31
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