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Get list from pandas DataFrame column headers
I want to get a list of the column headers from a pandas DataFrame. The DataFrame will come from user input so I won't know how many columns there will be or what they will be called.
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How to mkdir only if a directory does not already exist?
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Try mkdir -p:
mkdir -p foo
Note that this will also create any intermediate directories that don't exist; for instance,
mkdir -p foo/bar/baz
will create directories foo, foo/bar, and foo/bar/baz if they don't exist.
Some implementation like GNU mkdir include mkdir --parents as a more read...
Read first N lines of a file in python
... one won't work if the file doesn't have at least N lines. You are best to measure the performance against some typical data you will be using it with.
– John La Rooy
Nov 20 '09 at 0:47
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Why number 9 in kill -9 command in unix? [closed]
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Back in the day (by which I mean 4.xBSD or so) you couldn't use the mnemonics with the shell command, which is why the number 9 is written into an awful lot of old dusty-deck shell scripts.
– zwol
Mar 30 '12 at 23:...
Is there a method for String conversion to Title Case?
Are there any built in methods available to convert a string into Title Case format?
21 Answers
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Change Name of Import in Java, or import two classes with the same name
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There is no import aliasing mechanism in Java. You cannot import two classes with the same name and use both of them unqualified.
Import one class and use the fully qualified name for the other one, i.e.
import com.text.Formatter;
private Formatter t...
Are there pronounceable names for common Haskell operators? [closed]
...I never know how to pronounce the Haskell operators. Do they have "real" names? ?
5 Answers
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Ruby / Rails - Change the timezone of a Time, without changing the value
I have a record foo in the database which has :start_time and :timezone attributes.
11 Answers
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How do you use a variable in a regular expression?
I would like to create a String.replaceAll() method in JavaScript and I'm thinking that using a regex would be most terse way to do it. However, I can't figure out how to pass a variable in to a regex. I can do this already which will replace all the instances of "B" with "A" .
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Check if image exists on server using JavaScript?
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You could use something like:
function imageExists(image_url){
var http = new XMLHttpRequest();
http.open('HEAD', image_url, false);
http.send();
return http.status != 404;
}
Obviously you could use jQuery/similar to p...