I build program, when in one part I have some ranking, and I would like to give users option to customize it.
In my code I have a function that gets objects and returnes them packed with points and position in ranking (for now it calculates the arithmetic mean of some object's values).
My question is is it possible to give e.g. admin chance to write this function via admin panel and use it, so if he would like to one day use harmonic mean he could without changing source code?
Yes, you could just store a string in the database and exec() it with suitable arguments...
However, you'll have to be careful – Python code can practically never be sandboxed perfectly. In the event that you accept any arbitrary Python code for this, and someone with nefarious intents gets to your admin panel to change the expression, they can do practically anything.
In other words, don't use raw Python for the code you store.
Related
I have made a LazyRow that i now want to be able to get the scrollposition from. What i understand Scrollablerow has been deprecated. (correct me if im wrong) The thing is that i cant make a scrollablerow so i thought lets make a lazy one then. but i have no clue how to get scrollposition from the lazyrow. i know how to get index but not position if that eaven exists. here is what i have tried.
val scrollState = rememberScrollState()
LazyRow(scrollState = scrollstate){
}
For LazyScrollers, there are separate LazyStates.
I think there's just one, in fact, i.e. rememberLazyListState()
Pass that as the scroll state to the row and then you can access all kinds of info. For example, you could get the index of the first visible item, as well as its offset. There are direct properties for this stuff in the object returned by the above initialisation. You can also perform some more complex operations using the lazyListState.layoutInfo property that you get.
Also, ScrollableRow may be deprecated as a #Composable, but it is just refactored, a bit. Now, you can use the horozontalScroll() and verticalScroll() Modifiers, both of which accept a scrollState parameter, which expects the same object as the one you've created in the question.
Usually, you'd use LazyScrollers since they're not tough to implement and also are super-performant, but the general idea is that they are used with large datasets whereas non-lazy scrollers are okay for small sized lists and stuff. This is because the lazy ones cache only a small fraction of the entire list, making your UI peformant, which is not something regular scrollers do, and not a problem for small datasets.
They're like equivalents of RecyclerView from the View System
for a project, I am trying to create a web-app that, among other things, allows training of machine learning agents using python libraries such as Dedupe or TensorFlow. In cases such as Dedupe, I need to provide an interface for active learning, which I currently realize through jquery based ajax calls to a view that takes and sends the necessary training data.
The problem is that I need this agent object to stay alive throughout multiple view calls and be accessible by each individual call. I have tried realizing this via the built-in cache system using Memcached, but the serialization does not seem to keep all the info intact, and while I am technically able to restore the object from the cache, this appears to break the training algorithm.
Essentially, I want to keep the object alive within the application itself (rather than an external memory store) and be able to access it from another view, but I am at a bit of a loss of how to realize this.
If someone knows the proper technique to achieve this, I would be very grateful.
Thanks in advance!
To follow up with this question, I have since realized that the behavior shown seemed to have been an effect of trying to use the result of a method call from the object loaded from cache directly in the return properties of a view. Specifically, my code looked as follows:
#model is the object loaded from cache
#this returns the wrong object (same object as on an earlier call)
return JsonResponse({"pairs": model.uncertain_pairs()})
and was changed to the following
#model is the object loaded from cache
#this returns the correct object (calls and returns the model.uncertain_pairs() method properly)
uncertain = model.uncertain_pairs()
return JsonResponse({"pairs": uncertain})
I am unsure if this specifically happens due to an implementation from Dedupe or Django side or due to Python, but this has undoubtedly fixed the issue.
To return back to the question, Django does seem to be able to properly (de-)serialize objects and their properties in cache, as long as the cache is set up properly (see Apparent bug storing large keys in django memcached which I also had to deal with)
I am using openpyxl to read an excel file that will have changing values over time. The following function will take string inputs from the excel sheets to make frames for Tkinter.
def make_new_frame(strng, frame_location, frame_name, frame_list):
if not(frame_name in frame_list):
frame_list.append(frame_name)
exec("global %s" %(frame_name)) in globals()
exec("%s = Frame(%s)"%(frame_name, frame_location))
.... etc.
The code itself is quite long but I think this is enough of a snapshot to address my problem.
Now this results in the following error while parsing:
SyntaxError: function 'make_new_frame' uses import * and bare exec, which are illegal because it is a nested function
Everything in the code I included parsed and executed just fine several times, but after I added a few more lines in later versions in this function, it keeps spitting out the above error before executing the code. The error references the third line in the function, (which, I repeat, has been cleared in the past).
I added "in globals()" as recommended in another SO post, so that solution is not working.
There is a solution online here that uses setattr, which I have no idea how to use to create a widget without eventually using exec.
I would really appreciate if someone could tell me how to bypass the error while parsing or provide an alternative means for a dynamically changing set of frame names.
Quick Note:
I am aware that setting a variable as global in python is generally warned against, but I am quite certain that it will serve useful for my code
Edit 1: I have no idea why this was downvoted. If I have done something incorrectly, please let me know what it is so I can avoid doing so in the future.
I think this is an X/Y problem. You are asking for help with solution Y instead of asking for help on problem X.
If your goal is to create an unknown number of Frame objects based on external data, you can store references to the frame in a list or dictionary without having to resort to using exec and dynamically created variable names.
exec is a perfectly fine function, but is one of those things that you should never use until you fully understand why you should never use it.
Here's how to solve your actual problem without using exec:
frames = {}
def make_new_frame(strng, frame_location, frame_name, frames):
if not(frame_name in frames):
frames[frame_name] = Frame(frame_location)
return frames[frame_name]
With that, you now have a dictionary (frames) that includes a reference for every new frame by name. If you had a frame named "foo", for example, you could configure and pack it like this:
frames["foo"].configure(background="red", ...)
frames["foo"].pack(...)
If preserving the order of the frames is important you can use an OrderedDict.
I'm running my applications on CF 9. I created a CFC to concentrate my cookie handling instead of all the tags strewn about. It is simple. It has two attributes (name, value), and has 5 methods (setCookie, deleteCookie, verifyCookie, clearAllCookies, and init).
Since I wanted this method to be available throughout the application, I put this code in the onApplicationStart method of my application.cfc file:
application.oCookie = createObject("com.mycookie").init();
When I need to set a cookie in any code file I just call it like so:
application.oCookie.name="testCookieName";
application.oCookie.value="testCookieValue";
application.oCookie.setCookie();
My question is: Do I need to put a lock on this code each time I do this? If two separate users were to be on pages accessing this code at the same exact instant, can I end up with mixed up cookie values being set?
To make your oCookie thread-safe, it has to be a singleton (with no state) that only acts as a thin layer to the <cfcookie> or the cookie scope.
Therefore you should design your com.mycookie so that it accepts application.oCookie.setCookie(name, value) instead. And make sure you var-scope everything and don't store anything in the variables scope of mycookie.
And I don't think you need to use cflock.
If you haven't already, you may want to checkout WireBox.
I'm taking over a project and wanted to understand if this is common practice using SOAP. The process that is currently in place I have to query all the values before I do an update cause I need to pass back all the values that are not being updated. Does this sound right?
Example Values:
fname=phill
lname=pafford
address=123 main
phone:222-555-1212
So if I just wanted to update the phone number I need to query for the record, get all the values and submit these values for an update.
Example Update Values:
fname=phill
lname=pafford
address=123 main
phone:111-555-1212
I just want to know if this is common practice or should I change the functionality of this?
This is not specific to SOAP. It may simply be how the service is designed. In general, there will be fields that can only be updated if you have the original value: you can't add one to a field unless you know the original value, for instance. The service seems to have been designed for the general case.
I don't think that it is a very "common" practice. However I've seen cases where the old values are posted together with the new values, in order to validate that noone else has updated the values in the meantime.