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Detect if value is number in MySQL
... values ('00.00'),('+1'),('.123'),('-.23e4'),('12.e-5'),('3.5e+6'),('a'),('e6'),('+e0');
select
col1,
col1 + 0 as casted,
col1 REGEXP '^[+-]?[0-9]*([0-9]\\.|[0-9]|\\.[0-9])[0-9]*(e[+-]?[0-9]+)?$' as isNumeric
from myTable;
Result:
col1 | casted | isNumeric
-------|---------|----------
...
What characters are valid for JavaScript variable names?
...0-\u05ea\u05f0-\u05f2\u0620-\u064a\u066e\u066f\u0671-\u06d3\u06d5\u06e5\u06e6\u06ee\u06ef\u06fa-\u06fc\u06ff\u0710\u0712-\u072f\u074d-\u07a5\u07b1\u07ca-\u07ea\u07f4\u07f5\u07fa\u0800-\u0815\u081a\u0824\u0828\u0840-\u0858\u08a0\u08a2-\u08ac\u0904-\u0939\u093d\u0950\u0958-\u0961\u0971-\u0977\u0979-\u...
Why would finding a type's initializer throw a NullReferenceException?
...0007fe`8d4500e3 488b09 mov rcx,qword ptr [rcx]
000007fe`8d4500e6 498b03 mov rax,qword ptr [r11]
000007fe`8d4500e9 4c8b5068 mov r10,qword ptr [rax+68h]
000007fe`8d4500ed 48c744242800000000 mov qword ptr [rsp+28h],0
000007fe`8d4500f6 48894c2420 mov qword...
Set transparent background of an imageview on Android
...ctor.
Some opacity code:
Hex Opacity Values
100% — FF
95% — F2
90% — E6
85% — D9
80% — CC
75% — BF
70% — B3
65% — A6
60% — 99
55% — 8C
50% — 80
45% — 73
40% — 66
35% — 59
30% — 4D
25% — 40
20% — 33
15% — 26
10% — 1A
5% — 0D
0% — 00
You can also set opacit...
Remove columns from dataframe where ALL values are NA
...tion(x)!all(is.na(x))))),with=F]
examples using large data (30 columns, 1e6 rows)
big_data <- replicate(10, data.frame(rep(NA, 1e6), sample(c(1:8,NA),1e6,T), sample(250,1e6,T)),simplify=F)
bd <- do.call(data.frame,big_data)
names(bd) <- paste0('X',seq_len(30))
DT <- as.data.table(bd)
...
gradle build fails on lint task
...e inspiration from
https://android.googlesource.com/platform/tools/base/+/e6a5b9c7c1bca4da402de442315b5ff1ada819c7
(implementation:
https://android.googlesource.com/platform/tools/base/+/e6a5b9c7c1bca4da402de442315b5ff1ada819c7/build-system/gradle/src/main/groovy/com/android/build/gradle/interna...
Is Unit Testing worth the effort? [closed]
... community wiki
7 revs, 6 users 87%reefnet_alex
...
Windbg Step 2 分析程序堆栈实战 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...7680000 ntdll (pdb symbols) c:\websymbols\wntdll.pdb\ACE318E6A2F44F23A6CC5628F10A7DDC2\wntdll.pdb
我们发现MSVCR90D的pdb并没有被加载，是因为程序还没运行到，
3. 按F11
没有跳到源代码！
运行：src.path C:\Program Files (x86)\Microsoft Visual Studio 9...
Numpy - add row to array
...lock
print('numpy 1.14 takes {:.3f} micros per row'.format(duration * 1e6 / n_loops))
start_clock = perf_counter()
for count in range(0, n_loops):
py_array.append(py_row) # .15 micros
numpy_array = np.array(py_array) # 43.9 micros
duration = perf_counter() - start...
What's the $unwind operator in MongoDB?
...{
"result" : [
{
"_id" : ObjectId("4e6e4ef557b77501a49233f6"),
"title" : "this is my title",
"author" : "bob",
"tags" : "fun"
},
{
"_id" : ObjectId("4e...