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Using Emacs to recursively find and replace in text files not already open
...to find out how to do something like this which should be easy, that especially stops me from getting more used to using Emacs and instead starting up the editor I'm already familiar with. I use the example here fairly often in editing multiple files.
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Dynamic SELECT TOP @var In SQL Server
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this is great! all this time i thought i had to use dynamic sql.
– Laguna
Feb 20 '12 at 20:09
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How to check if a column exists in Pandas
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To check if one or more columns all exist, you can use set.issubset, as in:
if set(['A','C']).issubset(df.columns):
df['sum'] = df['A'] + df['C']
As @brianpck points out in a comment, set([]) can alternatively be constructed with curly...
vim repeat find next character 'x'
... and ;), to a different character than the repetition of an edit (.). This allows you to do fast searches and changes to the search results. If you want to replace some + in a line with * you could do something like this (skipping some characters and replacing others): f+r*;.;;.;.;;;.
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Sum a list of numbers in Python
...does integer division: it discards the remainder. To divide things through all the way, we need to use floating-point numbers. Fortunately, dividing an int by a float will produce a float, so we just use 2.0 for our divisor instead of 2.
Thus:
averages = [(x + y) / 2.0 for (x, y) in zip(my_list[:-...
Can I grep only the first n lines of a file?
... Is there a way to do this when using grep's -l option? I'd like to list all the files who's first 5 characters are RIFFD.
– James M. Lay
May 23 '17 at 19:20
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How do you check “if not null” with Eloquent?
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Actually here 'and' does nothing but it would do if first parameter would be an array. Here is the method prototype : public function where($column, $operator = null, $value = null, $boolean = 'and'); and location - ".....\vendor...
rbenv not changing ruby version
I installed rbenv according to the github directions. I am running OSX but I have tried this on a Ubuntu 12.04 VM and got the same results. The following is what i get in my terminal when I try to change ruby versions:
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Which characters need to be escaped in HTML?
...t in your document in a location where text content is expected1, you typically only need to escape the same characters as you would in XML. Inside of an element, this just includes the entity escape ampersand & and the element delimiter less-than and greater-than signs < >:
& becomes...
How do I enable language extensions from within GHCi?
... -XRankNTypes. The -X part is a compiler switch, by the way, extension is called just RankNTypes.
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