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Replace transparency in PNG images with white background
...ings with Image Magick "convert" operations, but either nothing happens at all or I get an error. I don't want to go to an intermediate JPG form because I don't want the artifacts. Of course it's easy to do this in Gimp or Photoshop or whatever, but I'd really rather script it from the command lin...
Naming of ID columns in database tables
...e wrong records.
If you would like to use the USING syntax that some dbs allow, you cannot if you use ID.
If you use ID you can easily end up with a mistaken join if you happen to be copying the join syntax (don't tell me that no one ever does this!)and forget to change the alias in the join con...
How to import other Python files?
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importlib was added to Python 3 to programmatically import a module.
It is just a wrapper around __import__, see the docs.
import importlib
moduleName = input('Enter module name:')
importlib.import_module(moduleName)
Note: the .py extension should be removed from mod...
Clearing purchases from iOS in-app purchase sandbox for a test user
...ases for an address: so tester+01@gmail.com and tester+02@gmail.com both really just go to tester@gmail.com. Probably other email hosts do the same. When you create a test account you need to introduce: first name, last name, email address, password, secret question, secret answer, date of birth, an...
Differences between Emacs and Vim
...and weeks till you will be happy with it and then you will learn new stuff all the time. You will be annoyed when you don't have access to it and constantly change your config. You won't be able to use other peoples emacs versions easily and it won't just be installed. It uses Lisp, which is great. ...
Xcode 4 hangs at “Attaching to (app name)”
...n in the simulator or iOS device. It was working perfectly in Xcode 3, but all of a sudden now when I press run the program stops at "Attaching to...". There doesn't seem to be any other info to help with this problem either.
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if A vs if A is not None:
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The statement
if A:
will call A.__nonzero__() (see Special method names documentation) and use the return value of that function. Here's the summary:
object.__nonzero__(self)
Called to implement truth value testing and the built-in operation ...
It is more efficient to use if-return-return or if-else-return?
...the if condition is false anyway.
Note that Python supports a syntax that allows you to use only one return statement in your case:
return A+1 if A > B else A-1
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Get all git commits since last tag
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If your current commit is also a tag and you want to dynamically get the changes since the previous tag, without knowing the latest tag nor previous tag name, you can do:
git log --oneline $(git describe --tags --abbrev=0 @^)..@
Note that @ is short for HEAD.
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How do I automatically sort a has_many relationship in Rails?
This seems like a really simple question but I haven't seen it answered anywhere.
5 Answers
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