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Purge or recreate a Ruby on Rails database
...ave a dev Ruby on Rails database full of data. I want to delete everything and rebuild the database. I'm thinking of using something like:
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Are loops really faster in reverse?
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is it worth to introduce a variable for array.length and use it in the for loop's head?
– ragatskynet
Oct 30 '12 at 10:13
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How can I determine whether a 2D Point is within a Polygon?
..., but macOS for example uses float for everything. macOS only knows points and a point can translate to one pixel, but depending on monitor resolution, it might translate to something else. On retina screens half a point (0.5/0.5) is pixel. Still, I never noticed that macOS UIs are significantly slo...
What is the difference between square brackets and parentheses in a regex?
.../^[789]\d{9}$/
/^[7-9]\d{9}$/
The explanation:
(a|b|c) is a regex "OR" and means "a or b or c", although the presence of brackets, necessary for the OR, also captures the digit. To be strictly equivalent, you would code (?:7|8|9) to make it a non capturing group.
[abc] is a "character class" th...
Javascript Drag and drop for touch devices [closed]
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You can use the Jquery UI for drag and drop with an additional library that translates mouse events into touch which is what you need, the library I recommend is https://github.com/furf/jquery-ui-touch-punch, with this your drag and drop from Jquery UI should ...
The definitive guide to form-based website authentication [closed]
...tion. The sections below will deal with patterns for sound practical auth, and how to avoid the most common security pitfalls.
To HTTPS or not to HTTPS?
Unless the connection is already secure (that is, tunneled through HTTPS using SSL/TLS), your login form values will be sent in cleartext, which al...
How to determine if binary tree is balanced?
... move to do some actual programming now. I'm working on binary trees now, and I was wondering what would be the best way to determine if the tree is height-balanced.
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Regex: Specify “space or start of string” and “space or end of string”
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You can use any of the following:
\b #A word break and will work for both spaces and end of lines.
(^|\s) #the | means or. () is a capturing group.
/\b(stackoverflow)\b/
Also, if you don't want to include the space in your match, you can use lookbehind/aheads.
(?<=\...
Change column type from string to float in Pandas
I want to convert a table, represented as a list of lists, into a Pandas DataFrame . As an extremely simplified example:
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What data type to use for hashed password field and what length?
... @Hippo: Please, don't use the username as the salt. Generate a random salt per user.
– Bill Karwin
Sep 15 '10 at 18:38
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