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How to migrate back from initial migration in Django 1.7?
I created a new app with some models and now I noticed that some of the models are poorly thought out. As I haven't committed the code the sensible thing would be to migrate the database to last good state and redo the migration with better models. In this case the last good state is database where ...
LINQ Ring: Any() vs Contains() for Huge Collections
...
Contains() is an instance method, and its performance depends largely on the collection itself. For instance, Contains() on a List is O(n), while Contains() on a HashSet is O(1).
Any() is an extension method, and will simply go through the collection, applyi...
Deleting array elements in JavaScript - delete vs splice
...ice(start, deleteCount) actually removes the element, reindexes the array, and changes its length.
> myArray = ['a', 'b', 'c', 'd']
["a", "b", "c", "d"]
> myArray.splice(0, 2)
["a", "b"]
> myArray
["c", "d"]
...
presentModalViewController:Animated is deprecated in ios6
... an image picker. But when I run it in the simulator, I have a memory leak and I get a warning about presentModalViewcontroller:animated being deprecated in iOS6. I also get dismissModalViewController:animated deprecated. I'm using the SDK 6.1.
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How would you compare jQuery objects?
...etty much nothing is required other than ensuring they are the same length and share identical nodes. Here is a small code snippet. You may even want to convert this into a jquery plugin for your own uses.
jQuery(function($) {
// Two separate jQuery references
var divs = $("div");
var divs2...
Convert UNIX epoch to Date object
I'm plotting and performing calculations on uniformly distributed time series. The timestamps are currently stored as integers representing the number of seconds since the UNIX epoch (e.g. 1352068320 ), but Date objects seem more appropriate for plotting. How can I do the conversion?
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How to set a stroke-width:1 on only certain sides of SVG shapes?
...ke then you can also use stroke-dasharray to do this, by making the dashes and gaps match up with the sides of the rectangle.
rect { fill: none; stroke: black; }
.top { stroke-dasharray: 0,50,150 }
.left { stroke-dasharray: 150,50 }
.bottom { stroke-dasharray: 100,50 }
.right { stroke-dasha...
Is it possible for a unit test to assert that a method calls sys.exit()
...ystemExit have an attribute code which is set to the proposed exit status, and the context manager returned by assertRaises has the caught exception instance as exception, so checking the exit status is easy:
with self.assertRaises(SystemExit) as cm:
your_method()
self.assertEqual(cm.exception...
How to create a new java.io.File in memory?
...tion then, is “it’s not possible”. This answer tries to be pragmatic and tell what the user could do instead. Andreas’ answer is clearly more thorough and a better (attempt at an) answer.
– haraldK
Jan 17 at 12:11
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How to read a .xlsx file using the pandas Library in iPython?
I want to read a .xlsx file using the Pandas Library of python and port the data to a postgreSQL table.
6 Answers
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