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How to automatically crop and center an image
...his version retains the img tag so that we do not lose the ability to drag or right-click to save the image. Credit to Parker Bennett for the opacity trick.
.center-cropped {
width: 100px;
height: 100px;
background-position: center center;
background-repeat: no-repeat;
overflow: ...
What is the apply function in Scala?
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Wikipedia
apply serves the purpose of closing the gap between Object-Oriented and Functional paradigms in Scala. Every function in Scala can be represented as an object. Every function also has an OO type: for instance, a function that takes an Int parameter and returns an Int will have OO typ...
How to exit if a command failed?
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Use { } in place of ( )
Introduce ; after exit and
spaces after { and before }
Since you want to print the message and exit only when the command fails ( exits with non-zero value) you need a || not an &&.
cmd1 && cmd2
will run cmd2 when cmd1 succeeds(exit value 0). Where as
...
Why doesn't list have safe “get” method like dictionary?
...name, not directly access the 37th item in the dictionary (which would be more like what you're asking of your list).
Of course, you can easily implement this yourself:
def safe_list_get (l, idx, default):
try:
return l[idx]
except IndexError:
return default
You could even monkeypatc...
Difference between pre-increment and post-increment in a loop?
Is there a difference in ++i and i++ in a for loop? Is it simply a syntax thing?
22 Answers
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Rails :dependent => :destroy VS :dependent => :delete_all
...e is an instantiation of all of your children. So, if you can't destroy it or if each has their own :dependent, its callbacks can be called.
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fol...
How do I include related model fields using Django Rest Framework?
...assroom
depth = 1
However, that will only include relationships for forward relationships, which in this case isn't quite what you need, since the teachers field is a reverse relationship.
If you've got more complex requirements (eg. include reverse relationships, nest some fields, but no...
Running multiple commands in one line in shell
...direct the output of a command into another command. What you are looking for is && operator to execute the next command only if the previous one succeeded:
cp /templates/apple /templates/used && cp /templates/apple /templates/inuse && rm /templates/apple
Or
cp /template...
Gradient of n colors ranging from color 1 and color 2
I often work with ggplot2 that makes gradients nice ( click here for an example ). I have a need to work in base and I think scales can be used there to create color gradients as well but I'm severely off the mark on how. The basic goal is generate a palette of n colors that ranges from x colo...
What is the difference between include and extend in Ruby?
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What you have said is correct. However there is more to it than that.
If you have a class Klazz and module Mod, including Mod in Klazz gives instances of Klazz access to Mod's methods. Or you can extend Klazz with Mod giving the class Klazz access...