So I'm trying to follow the Pebble SDK over here alongside the httpebble library.
Assume DictionaryIterator* received contains the following JSON payload:
{"0":["Oz Lotto","Powerball","TattsLotto","Super 66","Monday & Wednesday Lotto","The Pools"],"1":["17, 26, 38, 7, 36, 45, 9 (44) (41)","15, 37, 32, 6, 24, 10 (11)","37, 12, 15, 16, 42, 45 (6) (9)","1, 8, 5, 8, 8, 5","16, 40, 44, 8, 24, 15 (39) (3)","5, 17, 20, 22, 27, 31 (16)"]}
main.c:
I want to be able to extract the data to later store them into a list in my Pebble app. I'm having a bit of trouble grasping how a Tuple works though.
This is what I have so far, except I'm afraid I'm not sure how to actually extract values out of lotto_names and lotto_numbers.
void http_success(int32_t request_id, int http_status, DictionaryIterator* received, void* context) {
if (request_id != HTTP_COOKIE) {
return;
}
Tuple *lotto_names = dict_find(received, 0);
Tuple *lotto_numbers = dict_find(received, 1);
for (int i = 0; i < 5; i++) {
const char* lotto_name = lotto_names[i]; // ?
}
}
I've also asked the question over at the Pebble SDK forum. However noone has responded to my post. Any help would be appreciated.
In your example, the key "0" is associated to an array which is a form of nesting. As explained in httpebble documentation, there cannot be any nesting in the dictionary you return to `httpebble.
The key/value pairs attached to the request are sent as a flat JSON dictionary. There cannot be any nesting.
You need to rework your JSON data to send keys associated directly with values.
Related
I have an algorithm that outputs an array in a particular order. Example:
arr = [0, 1, 21, 2, 22, 23, 24, 25, 3, 27, 35, 36, 28, 37, 38, 4, 29, 5, 34, 6, 7, 8, 9, 10, 11, 12]
The array will be different depending on the user's input so the example above is only one of many undefined amount of possibilities; longer, shorter or different values (all values will be integers). So I wont be able to use case in my query.
I want to produce an SQL-Server query in my views.py to display all objects in my model in that exact order.
Here is my "query" at the moment but obviously it doesn't work.
test = QuoteAssemblies.objects.raw("""SELECT qmaQuoteAssemblyID,
qmaPartID,
qmaLevel,
qmaPartShortDescription,
qmaQuantityPerParent
FROM QuoteAssemblies
WHERE qmaQuoteAssemblyID IN arr
ORDER BY qmaQuoteAssemblyID = arr""")
In essence I want the query to be ordered by qmaQuoteAssemblyID as long as it is in the same order of the array (not ASC, DESC etc).
qmaQuoteAssemblyID = 0
qmaQuoteAssemblyID = 1
qmaQuoteAssemblyID = 21
qmaQuoteAssemblyID = 2
etc...
There is a similar example for MySQL Here. I just need something like that but for MSSQL. Cheers.
If your version of SQL Server supports JSON querying (i.e. 2016+), you can use openjson() function to number the elements of your array, and then use that number for sorting:
declare #Arr nvarchar(max) = '[0, 1, 21, 2, 22, 23, 24, 25, 3, 27, 35, 36, 28, 37, 38, 4, 29, 5, 34, 6, 7, 8, 9, 10, 11, 12]';
SELECT q.qmaQuoteAssemblyID,
q.qmaPartID,
q.qmaLevel,
q.qmaPartShortDescription,
q.qmaQuantityPerParent
FROM dbo.QuoteAssemblies q
inner join openjson(#Arr) ar on ar.[value] = q.qmaQuoteAssemblyID
ORDER BY ar.[key];
If you can't utilise JSON for this task, you will need to somehow produce a rowset with your array elements being correctly numbered, and use it in a similar fashion. There are lots of ways to achieve this, and it doesn't necessarily have to be done on server side. For example, you can create a 2 column key-value user-defined table type in your database, and provide the data as a parameter for your query.
Another approach is to supply the data in the form of XML, something like this:
declare #Ax xml = N'<r>
<i n="0" v="0" />
<i n="1" v="1" />
<i n="2" v="21" />
...
</r>';
SELECT q.qmaQuoteAssemblyID,
q.qmaPartID,
q.qmaLevel,
q.qmaPartShortDescription,
q.qmaQuantityPerParent
FROM dbo.QuoteAssemblies q
inner join #Ax.nodes('/r/i') ar(c) on ar.c.value('./#v', 'int') = q.qmaQuoteAssemblyID
ORDER BY ar.c.value('./#n', 'int');
Still, the numbering of XML nodes is better to be done by the application, as there is no efficient way to do this on the database side. That, and performance might be rather worse compared to the option 1.
I have one array like below:
Array = [21.2, 13.6, 86.2, 54.6, 76, 34, 78, 12, 90, 4];
Now I want to add Array values from the first index to the fourth index, and from the seventh index to the tenth.
I wrote this code but it did not work correctly.
s = 0
for I=1:10
if 1<=I<=4 | I>6
s = s + Array(I);
end
end
Please help me with this problem.
You can implement it without any kind of loop that may slow your code. To make those sums, you just need to use 'sum'. For further help, please read this. In your case, I'd do the following:
a = [21.2, 13.6, 86.2, 54.6, 76, 34, 78, 12, 90, 4];
b = sum(a(1:4))+sum(a(8:end));
Let's assume a multi-dimensional array
import numpy as np
foo = np.random.rand(102,43,35,51)
I know that those last dimensions represent a 2D space (35,51) of which I would like to index a range of rows of a column
Let's say I want to have rows 8 to 30 of column 0
From my understanding of indexing I should call
foo[0][0][8::30][0]
Knowing my data though (unlike the random data used here), this is not what I expected
I could try this that does work but looks ridiculous
foo[0][0][[8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30],0]
Now from what I can find in this documentation I can also use
something like:
foo[0][0][[8,30],0]
which only gives me the values of rows 8 and 30
while this:
foo[0][0][[8::30],0]
gives an error
File "<ipython-input-568-cc49fe1424d1>", line 1
foo[0][0][[8::30],0]
^
SyntaxError: invalid syntax
I don't understand why the :: argument cannot be passed here. What is then a way to indicate a range in your indexing syntax?
So I guess my overall question is what would be the proper pythonic equivalent of this syntax:
foo[0][0][[8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30],0]
Instead of
foo[0][0][8::30][0]
try
foo[0, 0, 8:30, 0]
The foo[0][0] part is the same as foo[0, 0, :, :], selecting a 2d array (35 x 51). But foo[0][0][8::30] selects a subset of those rows
Consider what happens when is use 0::30 on 2d array:
In [490]: np.zeros((35,51))[0::30].shape
Out[490]: (2, 51)
In [491]: np.arange(35)[0::30]
Out[491]: array([ 0, 30])
The 30 is the step, not the stop value of the slice.
the last [0] then picks the first of those rows. The end result is the same as foo[0,0,0,:].
It is better, in most cases, to index multiple dimensions with the comma syntax. And if you want the first 30 rows use 0:30, not 0::30 (that's basic slicing notation, applicable to lists as well as arrays).
As for:
foo[0][0][[8::30],0]
simplify it to x[[8::30], 0]. The Python interpreter accepts [1:2:3, 0], translating it to tuple(slice(1,2,3), 0) and passing it to a __getitem__ method. But the colon syntax is accepted in a very specific context. The interpreter is treating that inner set of brackets as a list, and colons are not accepted there.
foo[0,0,[1,2,3],0]
is ok, because the inner brackets are a list, and the numpy getitem can handle those.
numpy has a tool for converting a slice notation into a list of numbers. Play with that if it is still confusing:
In [495]: np.r_[8:30]
Out[495]:
array([ 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29])
In [496]: np.r_[8::30]
Out[496]: array([0])
In [497]: np.r_[8:30:2]
Out[497]: array([ 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28])
I'm following the 2014 WWDC tutorial 408: Swift Playgrounds using XCode Beta 3 (30 minutes in). The Swift syntax has changed since Beta 2.
var data = [27, 46, 96, 79, 56, 85, 45, 34, 2, 57, 29, 66, 99, 65, 66, 40, 40, 58, 87, 64]
func exchange<T>(data: [T], i: Int, j: Int) {
let temp = data[i]
data[i] = data[j] // Fails with error '#lvalue $T8' is not identical to 'T'
data[j] = temp // Fails with error '#lvalue $T5' is not identical to 'T'
}
exchange(data, 0 , 2)
data
Why I can't modify a mutable integer array in this way?
Because subroutine parameters are implicitly defined with let hence, non mutable. Try changing the declaration to:
func exchange<T>(inout data: [T], i: Int, j: Int) {
and the invocation to:
exchange(&date, 0, 2)
You can also use var but that would only allow the array to be modified within the subroutine. The big change for beta 3 was to make arrays really pass by value instead of just kind of sorta pass by value some of the time, but not the rest.
#David answer is correct, let me explain why: arrays (as well as dictionaries and strings) are value types (structs) and not reference types. When a value type has to be passed to a function, a copy of it is created, and the function works on that copy.
By using the inout modifier, the original array is passed instead, so in that case it's possible to make changes on it.
Basically, I have an array like this:
val base_length = Array(
0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
64, 80, 96, 112, 128, 160, 192, 224, 0
);
And when scala sees it, it wants to do this:
base_length: Array[Int] = Array(...)
But I would prefer for it to do this:
base_length: Array[Byte] = Array(...)
I tried:
val base_length = Array[Byte](...)
But scala says:
<console>:4: error: type arguments [Byte] do not conform to method apply's type
parameter bounds [A <: AnyRef]
val base_length = Array[Byte](1,2,3,4,5)
This seems to me to basically be telling me that the Array constructor wants to figure out what the type of the array is from the arguments. Normally that's awesome, but in this instance I have good reasons for wanting the array elements to be Bytes.
I have looked around for guidance on this, but I don't seem to be able to find anything. Any help would be great!
It should be:
C:\prog\>scala
Welcome to Scala version 2.7.5.final (Java HotSpot(TM) Client VM, Java 1.6.0_16).
Type in expressions to have them evaluated.
Type :help for more information.
scala> val gu: Array[Byte] = Array(18, 19, 20)
gu: Array[Byte] = Array(18, 19, 20)
This is not immutable. A Seq would be a step in that direction even if it is only a trait (as Christopher mentions in the comments) adding finite sequences of elements. A Scala List would be immutable.
Works in Scala 2.8.0:
Welcome to Scala version 2.8.0.r18502-b20090818020152 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_15).
Type in expressions to have them evaluated.
Type :help for more information.
scala> Array[Byte](0, 1, 2)
res0: Array[Byte] = Array(0, 1, 2)