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Why do I get AttributeError: 'NoneType' object has no attribute 'something'?
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You have a variable that is equal to None and you're attempting to access an attribute of it called 'something'.
foo = None
foo.something = 1
or
foo = None
print(foo.something)
Both will yield an AttributeError: 'NoneType'
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How does __proto__ differ from constructor.prototype?
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I've been trying to wrap my head around this recently and finally came up with this "map" that I think sheds full light over the matter
http://i.stack.imgur.com/KFzI3.png
I know I'm not the first one making this up but it was more interesting figuring it out that finding it ...
Converting a Java collection into a Scala collection
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JavaConversions (robinst's answer) and JavaConverters (Ben James's answer) have been deprecated with Scala 2.10.
Instead of JavaConversions use:
import scala.collection.convert.wrapAll._
as suggested by aleksandr_hramcov.
Instead of JavaConverters use:
i...
Insert string at specified position
...e) there should be a short explanation in your post maybe. I'll do it now and copy'n'paste from php.net: "Of course, if length is zero then this function will have the effect of inserting replacement into string at the given start offset."
– Wolfsblvt
Jan 23 '...
wpf: how to show tooltip when button disabled by command?
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Make tooltip visible for ALL disabled Buttons and Checkboxes:
<Window.Resources>
<Style TargetType="{x:Type Button}" BasedOn="{StaticResource {x:Type Button}}>
<Setter Property="ToolTipService.ShowOnDisabled" Value="true"/>
</Style&g...
Why does String.split need pipe delimiter to be escaped?
...lit is a regular expression, where in the '|' has a special meaning of OR, and a '\|' means a literal '|' so the string "\\|" means the regular expression '\|' which means match exactly the character '|'.
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Where can I view Tomcat log files in Eclipse?
... It refers to your workspace. In there you find a folder called .metadata and so on.
– Nils Schmidt
Feb 9 '10 at 23:08
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How is malloc() implemented internally? [duplicate]
...it).
So you have two methods of getting more memory from the kernel: sbrk and mmap. There are various strategies on how to organize the memory that you've got from the kernel.
One naive way is to partition it into zones, often called "buckets", which are dedicated to certain structure sizes. For e...
What is the difference between ArrayList.clear() and ArrayList.removeAll()?
...h faster since it doesn't have to deal with all those extra method calls.
And as Atrey points out, c.contains(..) increases the time complexity of removeAll to O(n2) as opposed to clear's O(n).
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Ruby on Rails: How can I revert a migration with rake db:migrate?
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Run the following command
rake db:migrate:down VERSION=<version>
where <version> is the version number of your migration file you want to revert.
eg. if you want to revert a migration with file name 3846656238_create_users.rb
r...