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What's the difference between array_merge and array + array?

... 72 The difference is: The + operator takes the union of the two arrays, whereas the array_merge fu...
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Using group by on multiple columns

... 2 Answers 2 Active ...
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How to install plugins to Sublime Text 2 editor?

... 182 You should have a Data/Packages folder in your Sublime Text 2 install directory. All you need to...
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What's the right OAuth 2.0 flow for a mobile app

...implement delegated authorization in a Web API for mobile apps using OAuth 2.0. According to specification, the implicit grant flow does not support refresh tokens, which means once an access token is granted for an specific period of time, the user must grant permissions to the app again once the t...
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How do I do multiple CASE WHEN conditions using SQL Server 2008?

... many WHEN as; CASE WHEN Col1 = 1 OR Col3 = 1 THEN 1 WHEN Col1 = 2 THEN 2 ... ELSE 0 END as Qty Or a Simple CASE expression CASE Col1 WHEN 1 THEN 11 WHEN 2 THEN 21 ELSE 13 END Or CASE within CASE as; CASE WHEN Col1 < 2 THEN CASE Col2 WHEN 'X' THE...
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Pandas DataFrame column to list [duplicate]

... 270 You can use the Series.to_list method. For example: import pandas as pd df = pd.DataFrame({...
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Finding quaternion representing the rotation from one vector to another

... Quaternion q; vector a = crossproduct(v1, v2); q.xyz = a; q.w = sqrt((v1.Length ^ 2) * (v2.Length ^ 2)) + dotproduct(v1, v2); Don't forget to normalize q. Richard is right about there not being a unique rotation, but the above should give the "shortest arc," which ...
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How can I do DNS lookups in Python, including referring to /etc/hosts?

... | edited Mar 7 '19 at 22:59 Justin M. Keyes 5,57011 gold badge2727 silver badges5656 bronze badges a...
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Dynamically select data frame columns using $ and a character value

...s a reproducible example below: # set seed for reproducibility set.seed(123) df <- data.frame( col1 = sample(5,10,repl=T) , col2 = sample(5,10,repl=T) , col3 = sample(5,10,repl=T) ) # We want to sort by 'col3' then by 'col1' sort_list <- c("col3","col1") # Use 'do.call' to call order. Se...