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C# switch on type [duplicate]
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You should probably do a check if that type is in the dictionary. Could do so fairly simple like this if(@switch.ContainsKey(typeof(MyType))) @switch[typeof(MyType)]();
– Automatico
Feb 26 '13 at 23:05
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python pandas dataframe to dictionary
...for to_dict. You can use it like this:
df.set_index('id').to_dict()
And if you have only one column, to avoid the column name is also a level in the dict (actually, in this case you use the Series.to_dict()):
df.set_index('id')['value'].to_dict()
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Javascript - removing undefined fields from an object [duplicate]
...key] === undefined && delete obj[key])
jsbin
Same example using if expression:
Object.keys(obj).forEach(key => {
if (obj[key] === undefined) {
delete obj[key];
}
});
If you want to remove the items from nested objects as well, you can use a recursive function:
const removeE...
ORA-30926: unable to get a stable set of rows in the source tables
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This is usually caused by duplicates in the query specified in USING clause. This probably means that TABLE_A is a parent table and the same ROWID is returned several times.
You could quickly solve the problem by using a DISTINCT in your query (in fact, if 'Y' is a constant val...
Why is pow(a, d, n) so much faster than a**d % n?
...into the future". Note, though, that the optimization could be extremely difficult or even impossible in general. For constant operands it could be optimized, but in x ** y % n, x could be an object that implements __pow__ and, based on a random number, returns one of several different objects imp...
How to find the sum of an array of numbers
...(function(acc, val) { return acc + val; }, 0)
)
Non-number inputs
If non-numbers are possible inputs, you may want to handle that?
console.log(
["hi", 1, 2, "frog"].reduce((a, b) => a + b)
)
let numOr0 = n => isNaN(n) ? 0 : n
console.log(
["hi", 1, 2, "frog"].reduce((...
How to find out what type of a Mat object is with Mat::type() in OpenCV
I am kind of confused with type() method of Mat object in OpenCV. If I have following lines:
6 Answers
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Uniq by object attribute in Ruby
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The hash method is better if you want to group by say album_id while (say) summing up num_plays.
– thekingoftruth
Sep 13 '13 at 22:59
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Catching error codes in a shell pipe
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If you really don't want the second command to proceed until the first is known to be successful, then you probably need to use temporary files. The simple version of that is:
tmp=${TMPDIR:-/tmp}/mine.$$
if ./a > $tmp.1
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Combine two or more columns in a dataframe into a new column with a new name
For example if I have this:
8 Answers
8
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