大约有 46,000 项符合查询结果（耗时：0.0769秒） [XML]
In Python, what is the difference between “.append()” and “+= []”?
...d will add one item to the list, while += will copy all elements of right-hand-side list into the left-hand-side list.
Update: perf analysis
Comparing bytecodes we can assume that append version wastes cycles in LOAD_ATTR + CALL_FUNCTION, and += version -- in BUILD_LIST. Apparently BUILD_LIST outw...
MySQL, Check if a column exists in a table with SQL
... query that will check if a specific table in MySQL has a specific column, and if not — create it. Otherwise do nothing. This is really an easy procedure in any enterprise-class database, yet MySQL seems to be an exception.
...
How does the const constructor actually work?
...calized" instance.
That is, all constant expressions begin canonicalized, and later these "canonicalized" symbols are used to recognize equivalence of these constants.
Canonicalization:
A process for converting data that has more than one possible representation into a "standard" canonical repres...
Automatically update version number
... in" stuff, you can't, as using 1.0.* or 1.0.0.* will replace the revision and build numbers with a coded date/timestamp, which is usually also a good way.
For more info, see the Assembly Linker Documentation in the /v tag.
As for automatically incrementing numbers, use the AssemblyInfo Task:
As...
How to capitalize the first character of each word in a string
...t into Java that capitalizes the first character of each word in a String, and does not affect the others?
51 Answers
...
How can I split and parse a string in Python?
...a fact that the string contains an underscore, you can even unpack the LHS and RHS into separate variables:
In [8]: lhs, rhs = "2.7.0_bf4fda703454".split("_", 1)
In [9]: lhs
Out[9]: '2.7.0'
In [10]: rhs
Out[10]: 'bf4fda703454'
An alternative is to use partition(). The usage is similar to the la...
Bash script to calculate time elapsed
...a script in bash to calculate the time elapsed for the execution of my commands, consider:
10 Answers
...
How to make CSS3 rounded corners hide overflow in Chrome/Opera
...w: hidden works in simple situations, but breaks in webkit based browsers and Opera when the parent is positioned relatively or absolutely.
...
What does ~~ (“double tilde”) do in Javascript?
I was checking out an online game physics library today and came across the ~~ operator. I know a single ~ is a bitwise NOT, would that make ~~ a NOT of a NOT, which would give back the same value, wouldn't it?
...
How to find out which fonts are referenced and which are embedded in a PDF document
...I'd like to inspect, which fonts are actually embedded in the pdf document and which are only referenced. Is there an easy (and cheap as in free) way to do that?
...