大约有 16,000 项符合查询结果（耗时：0.0296秒） [XML]
Generator Expressions vs. List Comprehension
...
John's answer is good (that list comprehensions are better when you want to iterate over something multiple times). However, it's also worth noting that you should use a list if you want to use any of the list methods. For example, the following code won't work:
def gen():
...
How do I specify unique constraint for multiple columns in MySQL?
I have a table:
14 Answers
14
...
What is the meaning of the term “free function” in C++?
While reading the documentation for boost::test, I came across the term "free function". What I understand is that a free function is any function that doesn't return anything (Its return type is void). But after reading further it seems that free functions also don't take any arguments. But I am no...
Can I split an already split hunk with git?
...t really is a fantastic feature.
I also discovered that a large hunk could be split into smaller hunks by hitting the s key, which adds to the precision of the commit.
But what if I want even more precision, if the split hunk is not small enough?
...
What do two question marks together mean in C#?
...se that, otherwise use what's to the right."
Note that you can use any number of these in sequence. The following statement will assign the first non-null Answer# to Answer (if all Answers are null then the Answer is null):
string Answer = Answer1 ?? Answer2 ?? Answer3 ?? Answer4;
Also it's wo...
Find the nth occurrence of substring in a string
This seems like it should be pretty trivial, but I am new at Python and want to do it the most Pythonic way.
21 Answers
...
Why can't decimal numbers be represented exactly in binary?
There have been several questions posted to SO about floating-point representation. For example, the decimal number 0.1 doesn't have an exact binary representation, so it's dangerous to use the == operator to compare it to another floating-point number. I understand the principles behind floating-po...
Insert the carriage return character in vim
I'm editing a network protocol frame stored a file in Unix ( \n newlines). I need to insert the carriage return character ( U+000D aka \r ). When I try to paste it from the clipboard ( "+p ) or type it using Ctrl + Shift + u - 000d , the linefeed is inserted ( U+000A ).
...
Android: Coloring part of a string using TextView.setText()?
...e .setText("") method while also coloring a part of the text (or making it bold, italic, transparent, etc.)and not the rest. For example:
...
Setting an environment variable before a command in Bash is not working for the second command in a
In a given shell, normally I'd set a variable or variables and then run a command. Recently I learned about the concept of prepending a variable definition to a command:
...