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Difference between Django's annotate and aggregate methods?
... Model:
class Books(models.Model):
name = models.CharField(max_length=100)
pages = models.IntegerField()
price = models.DecimalField(max_digits=5, decimal_places=3)
In Shell:
>>> Books.objects.all().aggregate(Avg('price'))
# Above code will give the Average of the price Colu...
Invoking JavaScript code in an iframe from the parent page
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edited Mar 10 '16 at 20:38
Chris
3,09311 gold badge2929 silver badges3737 bronze badges
a...
Accessing UI (Main) Thread safely in WPF
...owLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by \u003ca href=\"https://imgur.com/\"\u003e\u003csvg class=\"svg-icon\...
Calling clojure from java
...
To expand a little bit if you want to access def'd var in the namespace (i.e. (def my-var 10)) use this RT.var("namespace", "my-var").deref().
– Ivan Koblik
Nov 14 '12 at 9:40
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How to use UIVisualEffectView to Blur Image?
... Cesare
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answered Jun 6 '14 at 14:02
B.S.B.S.
20.9k1414 gold badge...
How to map and remove nil values in Ruby
...ect it to become the norm very soon.
For example:
numbers = [1, 2, 5, 8, 10, 13]
enum.filter_map { |i| i * 2 if i.even? }
# => [4, 16, 20]
In your case, as the block evaluates to falsey, simply:
items.filter_map { |x| process_x url }
"Ruby 2.7 adds Enumerable#filter_map" is a good read on ...
In Java, when should I create a checked exception, and when should it be a runtime exception? [dupli
...t balance first by using some other Account method - but this would seem a bit awkward.)
But also note Items 59: Avoid unnecessary use of checked exceptions and 57: Use exceptions only for exceptional conditions. As others have pointed out, this case may not warrant an exception at all. Consider re...
新浪是如何分析处理32亿条实时日志的？ - 更多技术 - 清泛网 - 专注C/C++及内核技术
...x open files等；App Level的优化如Java运行环境版本的选择，ES_HEAP_SIZE的设置，修改bulk index的queue size等，另外还设置了默认的index template，目的是更改默认的shard，replica数并将string改为not_analyzed，开启doc_values以应对elasticsearch进程OOM...
How to get city name from latitude and longitude coordinates in Google Maps?
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answered Feb 19 '10 at 13:03
cchenesonccheneson
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...
Setting an object to null vs Dispose()
...managed resource "nearly" directly, SafeHandle is your friend - it takes a bit of time to get going with, but it means you'll almost never need to write a finalizer again. You should usually only need a finalizer if you have a really direct handle on a resource (an IntPtr) and you should look to mov...