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SQL left join vs multiple tables on FROM line?
Most SQL dialects accept both the following queries:
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When to use Common Table Expression (CTE)
I have begun reading about Common Table Expression and cannot think of a use case where I would need to use them. They would seem to be redundant as the same can be done with derived tables. Is there something I am missing or not understanding well? Can someone give me a simple example of limitati...
In Python, if I return inside a “with” block, will the file still close?
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Yes, it acts like the finally block after a try block, i.e. it always executes (unless the python process terminates in an unusual way of course).
It is also mentioned in one of the examples of PEP-343 which is the specification for the with statement:
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Replacing blank values (white space) with NaN in pandas
...nt to find all values in a Pandas dataframe that contain whitespace (any arbitrary amount) and replace those values with NaNs.
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How to alias a table in Laravel Eloquent queries (or using Query Builder)?
Lets say we are using Laravel's query builder:
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How to use the pass statement?
I am in the process of learning Python and I have reached the section about the pass statement. The guide I'm using defines it as being a Null statement that is commonly used as a placeholder.
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How to sort a List alphabetically using Object name field
I have a List of Objects like List<Object> p .I want to sort this list alphabetically using Object name field. Object contains 10 field and name field is one of them.
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Why does one hot encoding improve machine learning performance?
... and used as training data for learning algorithms, it gives significantly better results with respect to prediction accuracy, compared to using the original matrix itself as training data. How does this performance increase happen?
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git diff renamed file
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The issue with the difference between HEAD^^ and HEAD is that you have an a.txt in both commits, so just considering those two commits (which is what diff does), there is no rename, there is a copy and a change.
To detect copies, you can use -C:
git dif...
Setting an int to Infinity in C++
I have an int a that needs to be equal to "infinity". This means that if
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