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Reference - What does this error mean in PHP?
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Notice: Undefined Index
Happens when you try to access an array by a key that does not exist in the array.
A typical example of an Undefined Index notice would be (demo)
$data = array('foo' => '42', 'bar');
echo $data['spinach'];
echo $...
Changing user agent on urllib2.urlopen
...from everyone's favorite Dive Into Python.
The short story: You can use Request.add_header to do this.
You can also pass the headers as a dictionary when creating the Request itself, as the docs note:
headers should be a dictionary, and will be treated as if add_header() was called with each k...
Stashing only staged changes in git - is it possible?
... STASH
Stage all your files that you need to stash.
Run git stash --keep-index. This command will create a stash with ALL of your changes (staged and unstaged), but will leave the staged changes in your working directory (still in state staged).
Run git stash push -m "good stash"
Now your "good st...
Deploying just HTML, CSS webpage to Tomcat
...he html file, which you want to be the starting page for your application, index.html
Start tomcat and point your browser to url "http://localhost:8080/MyApp". Your index.html page will pop up in the browser
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/etc/apt/sources.list" E212: Can't open file for writing
...ory
or the file name is not valid.
Vim has a builtin help system. I just quoted what it says to :h E212.
You might want to edit the file as a superuser as sudo vim FILE. Or if you don't want to leave your existing vim session (and now have proper sudo rights), you can issue:
:w !sudo tee % > ...
Add new row to dataframe, at specific row-index, not appended?
... 17
3 3 8 13 18
4 1 2 3 4
41 4 9 14 19
5 5 10 15 20
(Note we index r differently).
And finally, benchmarks:
library(microbenchmark)
microbenchmark(
rbind(existingDF[1:r,],newrow,existingDF[-(1:r),]),
insertRow(existingDF,newrow,r)
)
Unit: microseconds
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Allow Google Chrome to use XMLHttpRequest to load a URL from a local file
When trying to do a HTTP request using XMLHttpRequest from a local file, it basically fails due to Access-Control-Allow-Origin violation.
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Accessing members of items in a JSONArray with Java
...; jsonItems = IntStream.range(0, jsonArray.length())
.mapToObj(index -> (JSONObject) jsonArray.get(index))
.collect(Collectors.toList());
// you can access the array elements now
jsonItems.forEach(arrayElement -> System.out.println(arrayElement.get("a")));
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Find the Smallest Integer Not in a List
...(1) additional space. Just go through the array sequentially and for every index write the value at the index to the index specified by value, recursively placing any value at that location to its place and throwing away values > N. Then go again through the array looking for the spot where value...
TypeError: 'dict_keys' object does not support indexing
...ect which behaves a lot more like a set than a list. As such, it can't be indexed.
The solution is to pass list(d.keys()) (or simply list(d)) to shuffle.
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