大约有 11,400 项符合查询结果（耗时：0.0285秒） [XML]
Extract file name from path, no matter what the os/path format
Which Python library can I use to extract filenames from paths, no matter what the operating system or path format could be?
...
Why avoid increment (“++”) and decrement (“--”) operators in JavaScript?
...
My view is to always use ++ and -- by themselves on a single line, as in:
i++;
array[i] = foo;
instead of
array[++i] = foo;
Anything beyond that can be confusing to some programmers and is just not worth it in my view. For loops are an exception, as the...
Formula to determine brightness of RGB color
I'm looking for some kind of formula or algorithm to determine the brightness of a color given the RGB values. I know it can't be as simple as adding the RGB values together and having higher sums be brighter, but I'm kind of at a loss as to where to start.
...
How to check if PHP array is associative or sequential?
PHP treats all arrays as associative, so there aren't any built in functions. Can anyone recommend a fairly efficient way to check if an array contains only numeric keys?
...
How to swap keys and values in a hash
...
Ruby has a helper method for Hash that lets you treat a Hash as if it was inverted (in essence, by letting you access keys through values):
{a: 1, b: 2, c: 3}.key(1)
=> :a
If you want to keep the inverted hash, then Hash#...
Split (explode) pandas dataframe string entry to separate rows
...ld and create a new row per entry (assume that CSV are clean and need only be split on ','). For example, a should become b :
...
Is there XNOR (Logical biconditional) operator in C#?
I'm new to C# and could not find XNOR operator to provide this truth table:
4 Answers
...
Java String - See if a string contains only numbers and not letters
...ave a string that I load throughout my application, and it changes from numbers to letters and such. I have a simple if statement to see if it contains letters or numbers but, something isn't quite working correctly. Here is a snippet.
...
What is an existential type?
...icle Existential types . I gathered that they're called existential types because of the existential operator (∃). I'm not sure what the point of it is, though. What's the difference between
...
Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...
This doesn't answer your question directly, but it will give you the elements that are in common. This can be done with Paul Murrell's package compare:
library(compare)
a1 <- data.frame(a = 1:5, b = letters[1:5])
a2 <- data.frame(a = 1:3, b = letters[1:3])
compa...