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How to model type-safe enum types?
...rgumentException
}
// At REPL:
scala> val a = unitMatrixInt(3)
a: teste7.MatrixInt =
/ 1 0 0 \
| 0 1 0 |
\ 0 0 1 /
scala> a('row, 1) = a.row(0)
res41: teste7.MatrixInt =
/ 1 0 0 \
| 1 0 0 |
\ 0 0 1 /
scala> a('column, 2) = a.row(0)
res42: teste7.MatrixInt =
/ 1 0 1 \
| 0 1 0 |
\ 0 0...
What's the bad magic number error?
...ctory. Say if you create a new directory in django for seperating the unit tests into multiple files and place them in one directory then you also have to create the __init__.py file beside all the other files in new created test directory. otherwise it can give error like
Traceback (most recent ca...
How do I design a class in Python?
...a or because of some update/mutation which is performed.
Don't forget to test each class in isolation using unittest.
Also, there's no law that says classes must be mutable. In your case, for example, you have almost no mutable data. What you have is derived data, created by transformation func...
Length of generator output [duplicate]
...xecution (including memory consumption), will make you surprised:
```
1: test_list.py:8: 0.492 KiB
gen = (i for i in data*1000); t0 = monotonic(); len(list(gen))
('list, sec', 1.9684218849870376)
2: test_list_compr.py:8: 0.867 KiB
gen = (i for i in data*1000); t0 = monotonic(); len([i for i i...
Quickly find whether a value is present in a C array?
...s of utmost importance, the C compiler will most likely not produce the fastest code compared to what you can do with hand tuned assembly language. I tend to take the path of least resistance - for small routines like this, I just write asm code and have a good idea how many cycles it will take to e...
搭建高可用mongodb集群（二）—— 副本集 - 大数据 & AI - 清泛网 - 专注C/...
...集测试文件夹
#存放整个mongodb文件
mkdir -p /data/mongodbtest/replset
#存放mongodb数据文件
mkdir -p /data/mongodbtest/replset/data
#进入mongodb文件夹
cd /data/mongodbtest
3、下载mongodb的安装程序包
wget http://fastdl.mongodb.org/linux/mongodb-li...
html5 localStorage error with Safari: “QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to
...to removeItem are ignored.
I believe the simplest fix (although I haven't tested this cross browser yet) would be to alter the function isLocalStorageNameSupported() to test that you can also set some value.
https://github.com/marcuswestin/store.js/issues/42
function isLocalStorageNameSupported()...
Does Python have a string 'contains' substring method?
...class NoisyString(str):
def __contains__(self, other):
print(f'testing if "{other}" in "{self}"')
return super(NoisyString, self).__contains__(other)
ns = NoisyString('a string with a substring inside')
and now:
>>> 'substring' in ns
testing if "substring" in "a string...
urlencode vs rawurlencode?
... result in another environment, for example JavaScript.
In PHP urlencode('test 1') returns 'test+1' while rawurlencode('test 1') returns 'test%201' as result.
But if you need to "decode" this in JavaScript using decodeURI() function then decodeURI("test+1") will give you "test+1" while decodeURI("...
Share Large, Read-Only Numpy Array Between Multiprocessing Processes
...n use numpy.memmap. For example, if you have an array stored in disk, say 'test.array', you can use simultaneous processes to access the data in it even in "writing" mode, but your case is simpler since you only need "reading" mode.
Creating the array:
a = np.memmap('test.array', dtype='float32', ...