大约有 40,000 项符合查询结果（耗时：0.0400秒） [XML]
Python argparse mutual exclusive group
...
add_mutually_exclusive_group doesn't make an entire group mutually exclusive. It makes options within the group mutually exclusive.
What you're looking for is subcommands. Instead of prog [ -a xxxx | [-b yyy -c zzz]], you'd have:
p...
Is explicitly closing files important?
In Python, if you either open a file without calling close() , or close the file but not using try - finally or the " with " statement, is this a problem? Or does it suffice as a coding practice to rely on the Python garbage-collection to close all files? For example, if one does this:
...
Convert objective-c typedef to its string equivalent
...
This is really a C question, not specific to Objective-C (which is a superset of the C language). Enums in C are represented as integers. So you need to write a function that returns a string given an enum value. There are many ways to...
Why does “_” (underscore) match “-” (hyphen)?
...you are in a pattern context. e.g. inside a LIKE statement. When replacing all _ with an - : UPDATE sys_file set identifier = REPLACE(identifier, '_', '-') WHERE identifier LIKE '%\_%';. Notice the escaping inside LIKE and no escaping inside REPLACE. (I find it strange though that you are not in a p...
When to use in vs ref vs out
...ss you need ref.
It makes a big difference when the data needs to be marshalled e.g. to another process, which can be costly. So you want to avoid marshalling the initial value when the method doesn't make use of it.
Beyond that, it also shows the reader of the declaration or the call whether the ...
Google Maps API v3: How to remove all markers?
In Google Maps API v2, if I wanted to remove all the map markers, I could simply do:
31 Answers
...
How to prevent XSS with HTML/PHP?
...
Basically you need to use the function htmlspecialchars() whenever you want to output something to the browser that came from the user input.
The correct way to use this function is something like this:
echo htmlspecialchars($st...
Why are preprocessor macros evil and what are the alternatives?
I have always asked this but I have never received a really good answer; I think that almost any programmer before even writing the first "Hello World" had encountered a phrase like "macro should never be used", "macro are evil" and so on, my question is: why? With the new C++11 is there a real alte...
How to replace spaces in file names using a bash script
...whole question is about micro-optimizing more or less. Isn't it fun, after all? ;-)
– Michael Krelin - hacker
Apr 26 '10 at 18:33
17
...
Getting rid of all the rounded corners in Twitter Bootstrap
...global modification for a very boxy-not-round site, which is to get rid of all the rounded corners in Bootstrap...
16 Answ...