大约有 6,000 项符合查询结果(耗时:0.0281秒) [XML]
Where can I find “make” program for Mac OS X Lion?
Just upgraded my computer to Mac OS X Lion and went to terminal and typed "make" but it says:
-bash: make: command not found
...
How to generate all permutations of a list?
...
Combination (order does NOT matter):
print list(itertools.combinations('123', 2))
[('1', '2'), ('1', '3'), ('2', '3')]
Cartesian product (with several iterables):
print list(itertools.product([1,2,3], [4,5,6]))
[(1, 4), (1, 5), (1, 6),
(2, 4), (2, 5), (2, 6),
(3, 4), (3, 5), (3, 6)]
Cartesia...
How do I parse a string to a float or int?
...temptible lie
False True So false it becomes true
"123.456" True Decimal
" -127 " True Spaces trimmed
"\t\n12\r\n" True whitespace ignored
"NaN" True Not a number
"NaNanananaBATMAN" False ...
http HEAD vs GET performance
...EAD might work nicely.
For example, suppose you want to check if resource 123 exists. A 200 means "yes" and a 404 means "no":
HEAD /resources/123 HTTP/1.1
[...]
HTTP/1.1 404 Not Found
[...]
However, if the "yes" or "no" you want from your REST service is a part of the resource itself, rather th...
Import multiple csv files into pandas and concatenate into one DataFrame
...like an old fashioned aka manual way of doing things, esp. as the Hapood ecosystem has growing list of tools where you can perform sql queries directly on many different directories containing different file types (csv, json, txt, databases) as if it was one data source. There must be something si...
uint8_t can't be printed with cout
...
It doesn't really print a blank, but most probably the ASCII character with value 5, which is non-printable (or invisible). There's a number of invisible ASCII character codes, most of them below value 32, which is the blank actually.
You have to convert aa to u...
jQuery Data vs Attr?
...you'll need to use .attr():
HTML:
<a id="foo" href="#" data-color="ABC123"></a>
<a id="bar" href="#" data-color="654321"></a>
JS:
$('#foo').data('color').length; //6
$('#bar').data('color').length; //undefined, length isn't a property of numbers
$('#foo').attr('data-col...
How can I eliminate slow resolving/loading of localhost/virtualhost (a 2-3 second lag) on Mac OS X L
Since setting up my development environments on Mac OS X Lion (brand new macbook air purchased in January 2012), I have noticed that resolving to a virtual host is very slow (around 3 seconds) the first time but after that is fast as long as I continue loading it regularly.
...
How do I perform an insert and return inserted identity with Dapper?
...Username = "lorem ipsum",
Phone = "555-123",
Email = "lorem ipsum"
},
tran);
Return inserted object with ID:
If you wanted you could get Phone and Email or even th...
Strangest language feature
...
Or, more usefully, "0123456789abcdef"[x & 0xf]
– Dipstick
Jan 3 '10 at 15:33
17
...