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How do you validate a URL with a regular expression in Python?
I'm building an app on Google App Engine. I'm incredibly new to Python and have been beating my head against the following problem for the past 3 days.
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What's the difference between a single precision and double precision floating point operation?
What is the difference between a single precision floating point operation and double precision floating operation?
11 Answ...
Difference between variable declaration syntaxes in Javascript (including global variables)?
...gh in practical terms they're not usually big ones.
There's a fourth way, and as of ES2015 (ES6) there's two more. I've added the fourth way at the end, but inserted the ES2015 ways after #1 (you'll see why), so we have:
var a = 0; // 1
let a = 0; // 1.1 (new with ES2015)
const a = 0; //...
How can you find and replace text in a file using the Windows command-line environment?
I am writing a batch file script using Windows command-line environment and want to change each occurrence of some text in a file (ex. "FOO") with another (ex. "BAR"). What is the simplest way to do that? Any built in functions?
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What is the difference between Raising Exceptions vs Throwing Exceptions in Ruby?
Ruby has two different exceptions mechanisms: Throw/Catch and Raise/Rescue.
3 Answers
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Can I recover a branch after its deletion in Git?
...branch? Is there a way to go back as if I didn't run the delete branch command?
20 Answers
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pip installing in global site-packages instead of virtualenv
...r instead of the one in the virtualenv folder. Here's how I set up Python3 and virtualenv on OS X Mavericks (10.9.1):
30 An...
How do I import CSV file into a MySQL table?
...ed HeidiSQL. It gives you a graphical interface to build the LOAD DATA command; you can re-use it programmatically later.
Screenshot: "Import textfile" dialog
To open the Import textfile" dialog, go to Tools > Import CSV file:
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Vagrant ssh authentication failure
...lic key to ~/.ssh/authorized_keys on the Vagrant VM. You can do it by copy-and-pasting or using a tool like ssh-copy-id (user: root password: vagrant port: 2222) ssh-copy-id '-p 2222 root@127.0.0.1'
If still does not work try this:
Remove insecure_private_key file from c:\Users\USERNAME\.vagrant...
Are 2^n and n*2^n in the same time complexity?
... answer this question.
The definition is that f(x) belongs to O(g(x)) if and only if the limit limsupx → ∞ (f(x)/g(x)) exists i.e. is not infinity. In short this means that there exists a constant M, such that value of f(x)/g(x) is never greater than M.
In the case of your question let f(n) ...