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TransactionManagementError “You can't execute queries until the end of the 'atomic' block” while usi
...ementError when trying to save a Django User model instance and in its post_save signal, I'm saving some models that have the user as the foreign key.
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How to check if a Unix .tar.gz file is a valid file without uncompressing?
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What about just getting a listing of the tarball and throw away the output, rather than decompressing the file?
tar -tzf my_tar.tar.gz >/dev/null
Edited as per comment. Thanks zrajm!
Edit as per comment. Thanks Frozen Flame! This test in no way implies integrity ...
How to Convert all strings in List to lower case using LINQ?
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Easiest approach:
myList = myList.ConvertAll(d => d.ToLower());
Not too much different than your example code. ForEach loops the original list whereas ConvertAll creates a new one which you need to reassign.
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How to hide UINavigationBar 1px bottom line
..., a custom background image must
also be set with the setBackgroundImage(_:for:) method. If the default
background image is used, then the default shadow image will be used
regardless of the value of this property.
So:
let navigationBar = navigationController!.navigationBar
navigationBar.se...
Hook up Raspberry Pi via Ethernet to laptop without router? [closed]
I'm working on a balloon project with a Raspberry Pi. When we potentially recover the Raspberry Pi, it will most likely be in a rural location and I'd like to turn off the Pi at that point safely.
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input type=“submit” Vs button tag are they interchangeable?
...an INPUT element whose type is set to "image", but the BUTTON element type allows content.
So for functionality only they're interchangeable!
(Don't forget, type="submit" is the default with button, so leave it off!)
shar...
各编程语言读写文件汇总 - C/C++ - 清泛网 - 专注C/C++及内核技术
各编程语言读写文件汇总all_programming_language_file_read_write_summary读写文件本来是非常基础的代码，但工作学习中难免会有遗忘，有时又难以翻看自己写过的代码，网上搜索更是五花八门让人头大，鉴于此，清泛网 读写文件本来是...
Rails Object to hash
...ly attributes, then you can get them by:
@post.attributes
Note that this calls ActiveModel::AttributeSet.to_hash every time you invoke it, so if you need to access the hash multiple times you should cache it in a local variable:
attribs = @post.attributes
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Scala @ operator
...n itself? That would be accomplished with this:
o match {
case x @ Some(_) => println(x)
case None =>
}
Note that @ can be used at any level, not just at the top level of the matching.
share
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Converting NumPy array into Python List structure?
...ype" (in a list). If you want to preserve the numpy data types, you could call list() on your array instead, and you'll end up with a list of numpy scalars. (Thanks to Mr_and_Mrs_D for pointing that out in a comment.)
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