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What to add for the update portion in ConcurrentDictionary AddOrUpdate
...e you don't distinguish between add and update) this would be:
var sessionId = a.Session.SessionID.ToString();
userDic.AddOrUpdate(
authUser.UserId,
sessionId,
(key, oldValue) => sessionId);
I.e. the Func always returns the sessionId, so that both Add and Update set the same value.
BTW:...
how do you filter pandas dataframes by multiple columns
To filter a dataframe (df) by a single column, if we consider data with male and females we might:
6 Answers
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Selecting pandas column by location
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How to use the 'sweep' function
... matrix you defined, you will do:
sweep (M, 1, c(1: 4), "+")
I frankly did not understand the definition in the R documentation either, I just learned by looking up examples.
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Undo svn add without reverting local edits
I accidentally ran svn add * and added a bunch of files that shouldn't be in the repository. I also have local edits in some files that I want to keep. Is there a simple way to just undo the svn add without reverting the local edits? The main suggestion I see on Google is svn revert , which sup...
dplyr: “Error in n(): function should not be called directly”
... Exactly... the conflict was between summarise or summarize. I also accidentally loaded plyr and dplyr packages in one of my project and realized this conflict. nice work mate.
– Manoj Kumar
Aug 2 '16 at 18:19
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Why use 'git rm' to remove a file instead of 'rm'?
...o a checkout of master to get out of detached head state because I knew I didn't have any uncommitted changes. If you haven't committed your changes you may want to do a git stash, but I'm relatively new to git so I don't know the exact command. If you have come here in or after 2014, I hope this an...
Literal suffix for byte in .NET?
...
Could you provide a link to the C# 7 document where 0b is covered.
– user3613932
Mar 19 at 23:54
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The remote end hung up unexpectedly while git cloning
...an this buffer size, HTTP/1.1 and Transfer-Encoding: chunked is used to avoid creating a massive pack file locally. Default is 1 MiB, which is sufficient for most requests.
Even for the clone, that can have an effect, and in this instance, the OP Joe reports:
[clone] works fine now
Note: i...
Will using goto leak variables?
...It is a myth that goto is some low-level construct that allows you to override C++'s built-in scoping mechanisms. (If anything, it's longjmp that may be prone to this.)
Consider the following mechanics that prevent you from doing "bad things" with labels (which includes case labels).
1. Label sc...