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Determine the data types of a data frame's columns
...ation as a vector (i.e. you don't need it to do something else programmatically later), just use str(foo).
In both cases foo would be replaced with the name of your data frame.
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std::vector versus std::array in C++
... should one be preferred over another? What are the pros and cons of each? All my textbook does is list how they are the same.
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When should I use std::thread::detach?
... completes. This is easy to understand, but what's the difference between calling detach() and not calling it?
5 Answers
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Django - limiting query results
...s are lazy. That means a query will hit the database only when you specifically ask for the result.
So until you print or actually use the result of a query you can filter further with no database access.
As you can see below your code only executes one sql query to fetch only the last 10 items.
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How to use a WSDL
... of the defined methods on the WSDL contract.
Instantiate the client and call the methods you want to call - that's all there is!
YourServiceClient client = new YourServiceClient();
client.SayHello("World!");
If you need to specify the remote URL (not using the one created by default), you can e...
HttpSecurity, WebSecurity and AuthenticationManagerBuilder
...icationManagerBuilder) is used to establish an authentication mechanism by allowing AuthenticationProviders to be added easily: e.g. The following defines the in-memory authentication with the in-built 'user' and 'admin' logins.
public void configure(AuthenticationManagerBuilder auth) {
auth
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Cleaning `Inf` values from an R dataframe
...ption 1
Use the fact that a data.frame is a list of columns, then use do.call to recreate a data.frame.
do.call(data.frame,lapply(DT, function(x) replace(x, is.infinite(x),NA)))
Option 2 -- data.table
You could use data.table and set. This avoids some internal copying.
DT <- data.table(dat)...
How to check all checkboxes using jQuery?
...I have tried to create a little script for my application. I want to check all checkboxes but it isn't working correctly.
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Remove blank lines with grep
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Try the following:
grep -v -e '^$' foo.txt
The -e option allows regex patterns for matching.
The single quotes around ^$ makes it work for Cshell. Other shells will be happy with either single or double quotes.
UPDATE: This works for me for a file with blank lines or "all white ...
disable maven download progress indication
...--no-transfer-progress will suppress the output of downloading messages at all without suppressing the other output.
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