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How to check if a column exists in Pandas
...ments, you can use the get() method for DataFrames. For performing the sum based on the question:
df['sum'] = df.get('A', df['B']) + df['C']
The DataFrame get method has similar behavior as python dictionaries.
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Relative URL to a different port number in a hyperlink?
... For instance this modified code just worked for me and moves me from any base port to port 8069 (replace your port as required)
<div>
<a href="http://<?php print
$_SERVER{'SERVER_NAME'}; ?>:8069"><img
src="images/example.png"/>Example Base (http)</a>
<...
Haskell: Converting Int to String
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An example based on Chuck's answer:
myIntToStr :: Int -> String
myIntToStr x
| x < 3 = show x ++ " is less than three"
| otherwise = "normal"
Note that without the show the third line will not compile.
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How to change the type of a field?
... @SundarBons yes you are re-writing a field across your database, this is a big deal no matter how you do it. If you were using SQL and this was a big table you would probably have to take some down time.
– Gates VP
Jun 28 '16 at 18:16
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Convert RGBA PNG to RGB with PIL
...e's a version that's much simpler - not sure how performant it is. Heavily based on some django snippet I found while building RGBA -> JPG + BG support for sorl thumbnails.
from PIL import Image
png = Image.open(object.logo.path)
png.load() # required for png.split()
background = Image.new("R...
Get all elements but the first from an array
...ySegment<> implements IList<>, IReadOnlyList<> and their base interfaces (including IEnumerable<>), so you can for example pass an ArraySegment<> to string.Join.
– Jeppe Stig Nielsen
Jan 25 '17 at 8:49
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Is there a concurrent List in Java's JDK?
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If you don't care about having index-based access and just want the insertion-order-preserving characteristics of a List, you could consider a java.util.concurrent.ConcurrentLinkedQueue. Since it implements Iterable, once you've finished adding all the items, yo...
Scala: What is a TypeTag and how do I use it?
...ixes that come from different mirrors), 2) Both TypeTag and AbsTypeTag are based on mirrors. The difference is that TypeTag only allows fully instantiated types (i.e. without any type parameters or references abstract type members), 3) A detailed explanation is here: stackoverflow.com/questions/1209...
Is there a combination of “LIKE” and “IN” in SQL?
In SQL I (sadly) often have to use " LIKE " conditions due to databases that violate nearly every rule of normalization. I can't change that right now. But that's irrelevant to the question.
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Globally catch exceptions in a WPF application?
...emory, or lost network connectivity while you're trying to save to the database.
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