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What's the difference between echo, print, and print_r in PHP?
...play strings. The differences are subtle: print has a return value of 1 so it can be used in expressions whereas echo has a void return type; echo can take multiple parameters, although such usage is rare; echo is slightly faster than print. (Personally, I always use echo, never print.)
var_dump pr...
What is getattr() exactly and how do I use it?
...e getattr() function . The problem is that I still can't grasp the idea of its usage. The only thing I understand about getattr() is that getattr(li, "pop") is the same as calling li.pop .
...
Rolling median algorithm in C
I am currently working on an algorithm to implement a rolling median filter (analogous to a rolling mean filter) in C. From my search of the literature, there appear to be two reasonably efficient ways to do it. The first is to sort the initial window of values, then perform a binary search to inser...
How to clear the interpreter console?
Like most Python developers, I typically keep a console window open with the Python interpreter running to test commands, dir() stuff, help() stuff , etc.
...
How to deal with SettingWithCopyWarning in Pandas?
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The SettingWithCopyWarning was created to flag potentially confusing "chained" assignments, such as the following, which does not always work as expected, particularly when the first selection returns a copy. [see GH5390 and GH5597 for ...
Python Logging (function name, file name, line number) using a single file
...s I am inserting debug commands as the first line of each function's body with the goal of logging the function's name as well as the line number (within the code) where I send a message to the log output. Finally, since this application comprises of many files, I want to create a single log file so...
'printf' vs. 'cout' in C++
... is a difference - std::cout is C++, and printf is C (however, you can use it in C++, just like almost anything else from C). Now, I'll be honest here; both printf and std::cout have their advantages.
Real differences
Extensibility
std::cout is extensible. I know that people will say that printf ...
How to validate an e-mail address in swift?
...icate(format:"SELF MATCHES %@", emailRegEx)
return emailPred.evaluate(with: email)
}
for versions of Swift earlier than 3.0:
func isValidEmail(email: String) -> Bool {
let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
let emailPred = NSPredicate(format:"SELF MAT...
How do I migrate a model out of one django app and into a new one?
I have a django app with four models in it. I realize now that one of these models should be in a separate app. I do have south installed for migrations, but I don't think this is something it can handle automatically. How can I migrate one of the models out of the old app into a new one?
...
What are the differences between the threading and multiprocessing modules?
...
What Giulio Franco says is true for multithreading vs. multiprocessing in general.
However, Python* has an added issue: There's a Global Interpreter Lock that prevents two threads in the same process from running Python code at the same time. This means that if yo...