I have been developing a full-stack application that checks for files and uploads them to a cloud. However, I have come across an interesting problem that I was not able to solve.
I have a problem with instantiating a class, as you will see below:
class UploadFastq:
def __int__(self,
some_list, some_str, some_obj, **kwargs):
self.some_list = some_list
self.some_obj = some_obj
self.some_str = some_str
def process(self):
self.some_methods_calling_processes()
...
As you can imagine, I have trimmed the original code for privacy concerns (company dictates, sorry). This class is to handle some-backend related processes, and arguments only contain back related variables. Also, this class is on the different py script, which imports again back-related functions.
Now, the problem is, when I import to another script and try to call and instantiate the class, something funny happens...
from lib.some_back_related_script import UploadFastq
uploads = UploadFastq(some_list=the_list,some_str=the_str,some_obj=the_obj)
uploads.process
OUTPUT:
TypeError: UploadFastq() takes no arguments
I have looked if there are indentation problems, I could not find any. (I am using PyCharm as IDE, and reformatting the file also did not solve)
I have also tried this on an another script(the gui script) and could partially solve it as:
from lib.some_back_related_script import UploadFastq
uploader = UploadFastq()
uploader.__int__( ##TODO how is this possible???)
some_list=the_list,some_str=the_str,some_obj=the_obj
)
However, on the script the class suppose to be called, "__init__" method did not solve the case, and produced this error:
TypeError: UploadFastq.__init__() takes exactly one argument (the instance to initialize)
At this point I am clueless about what is going on and how to solve it. I have experiencing something like this for first time. I also could not find this kind of problem on the internet. soo, I would be much grateful if you could explain how to approach the problem.
P.S.: I work as a bioinformatician/python developer for a quite time and I found many many solutions on this platform. But, this is actually my first question on the stackoverflow!!!
Cheers!
You mispelled the constructor name __init__ as __int__ :
def __int__(self, some_list, some_str, some_obj, **kwargs):
Thus the default constructor (which takes as arguments only the "instance to initialize") was called, and the interpreter is complaining about the given arguments.
TypeError: UploadFastq.__init__() takes exactly one argument (the instance to initialize)
Related
I am using PyObj-C and am making some methods in a python file to read and write files using NSDocument, which uses the abstract NSFileCoordinater class. Accessing files this way instead of just using python's open let's these classes handle things for me such as preventing files from being edited from more than one program at a time or giving enough time for read/write operations to finish before it could get deadlocked.
These features are very important, and the app I ma building I want to be up to standard as much as I can here.
I have this code that instantiates a NSDocument object that contains the content of whatever file path you put into it, as a function:
#classmethod
def write(cls, file: str):
path = NSURL.fileURLWithPath_(file)
ext = file.split('.')[-1]
doc = NSDocument.alloc().initWithContentsOfURL_ofType_error_(path, ext, None)
When I call this function with a valid file path I get this error:
File "/Users/user123/PycharmProjects/shoutout/src/sutils/cfiles.py", line 27, in write
doc = NSDocument.alloc().initWithContentsOfURL_ofType_error_(path, ext, None)
objc.error: NSInternalInconsistencyException - readFromData:ofType:error: is a subclass responsibility but has not been overridden.
I have tried to find forums both objective-c, swift, or pyobj-c based as it were asking any keywords such as objective-c is a subclass responsibility but has not been overridden on google, and checked stackoverflow, and github for existing posts on this error but I could find none.
As I understand it Objective-C being polymorphic, has my method initWithContentsOfURL:ofType:error: call readFromData:ofType:error, among other ones at the same time. I don't understand exactly however what it means when it's saying that "is a subclass responsibility but has not been overridden." I am not sure also about what it means to override a class or a one being a responsibility so that doesn't help on my part.
A NSInternalInconsistencyException means a "when an internal assertion fails and implies an unexpected condition within the called code." Not sure what a internal "assertion" is either or what this could mean.
Any idea of what I could do to fix this?
NSDocument is an abstract class that requires you to subclass and implement a number of methods to make it usable. This is document in Apple's documentation for the class.
the older Document-Baed App Programming Guide for Mac gives more information on this.
I'm currently writing code in Python 2.7, which involves creating an object, in which I have two class methods and other regular methods. I need to use this specific combination of methods because of the larger context of the code I am writing- it's not relevant to this question, so I won't go into depth.
Within my __init__ function, I am creating a Pool (a multiprocessing object). In the creation of that, I call a setup function. This setup function is a #classmethod. I define a few variables in this setup function by using the cls.variablename syntax. As I mentioned, I call this setup function within my init function (inside the Pool creation), so these variables should be getting created, based on what I understand.
Later in my code, I call a few other functions, which eventually leads to me calling another #classmethod within the same object I was talking about earlier (same object as the first #classmethod). Within this #classmethod, I try to access the cls.variables I created in the first #classmethod. However, Python is telling me that my object doesn't have an attribute "cls.variable" (using general names here, obviously my actual names are specific to my code).
ANYWAYS...I realize that's probably pretty confusing. Here's some (very) generalized code example to illustrate the same idea:
class General(object):
def __init__(self, A):
# this is correct syntax based on the resources I'm using,
# so the format of argument isn't the issue, in case anyone
# initially thinks that's the issue
self.pool = Pool(processes = 4, initializer=self._setup, initargs= (A, )
#classmethod
def _setup(cls, A):
cls.A = A
#leaving out other functions here that are NOT class methods, just regular methods
#classmethod
def get_results(cls):
print cls.A
The error I'm getting when I get to the equivalent of the print cls.A line is this:
AttributeError: type object 'General' has no attribute 'A'
edit to show usage of this code:
The way I'm calling this in my code is as such:
G = General(5)
G.get_results()
So, I'm creating an instance of the object (in which I create the Pool, which calls the setup function), and then calling get_results.
What am I doing wrong?
The reason General.A does not get defined in the main process is that multiprocessing.Pool only runs General._setup in the subprocesses. This means that it will not be called in the main process (where you call Pool).
You end up with 4 processes where in each of them there is General.A is defined, but not in the main process. You don't actually initialize a Pool like that (see this answer to the question How to use initializer to set up my multiprocess pool?)
You want an Object Pool which is not natively impemented in Python. There's a Python Implementation of the Object Pool Design Pattern question here on StackOverflow, but you can find a bunch by just searching online.
I made a command in django which calls a function.
That function does a django orm call:
def get_notes():
notes = Note.objects.filter(number=2, new=1)
return [x.note for x in notes]
I want to patch the actual lookup:
#mock.patch('Note.objects.filter', autospec=True)
def test_get_all_notes(self, notes_mock):
get_notes()
notes_mock.assert_called_once_with(number=2, new=1)
I get the following assertion error:
AssertionError: Expected call: filter(number=2, new=1)
Actual call: filter(number=2, new=1)
I search on google and stackoverflow for hours, but I still haven't a clue.
Can anyone point me in the right direction, I think it might be an obvious mistake I'm making...
AFAIK you can't use patch() like this. Patch target should be a string in the form package.module.ClassName. I don't know much about django but I suppose Note is a class so Note.objects.filter is not something you can import and hence use in patch(). Also I don't think patch() can handle attributes. Actually I don't quite understand why the patch works at all.
Try using patch.object() which is specifically designed to patch class attributes. It implies Note is already imported in your test module.
#mock.patch.object(Note, 'objects')
def test_get_all_notes(self, objects_mock):
get_notes()
objects_mock.filter.assert_called_once_with(number=2, new=1)
I've removed autospec because I'm not sure it will work correctly in this case. You can try putting it back if it works.
Another option might be to use patch() on whatever you get with type(Note.objects) (probably some django class).
As I've said I don't know much about django so I'm not sure if these things work.
relative noob here! I'm running 2.7, if that helps.
I'm trying to call a function defined in my main application class in a different function (I think that's called inheritance?) But I keep having problems with the number of args I put into my function!
Here's the function (is it called a method? if not, what's a method) I'm trying to call:
def student_list_updater(self, list):
self.StudentListDisplay.delete(0, END)
for student in list:
self.StudentListDisplay.insert(END, student)
And here's the function I'm calling it in (it's inheriting student_list_updater, right?):
def OnRemoveClick(self, student_list_updater):
self.student_list_updater = student_list_updater
index = self.StudentListDisplay.curselection()
index = int(index[0])
del student_list_temp[index]
self.student_list_updater(student_list_temp)
Thank you for the help in advance!
It's a little difficult to understand your question without more of the code, but hopefully this answer points you in the right direction.
First, to clarify, methods are just functions that can be accessed through an instance of a class, so yes, these are methods, but they're also functions--don't get too hung up on it. Next, I don't think inheritance is necessary here--inheritance will be one class inheriting attributes from another, and I believe all of your methods are only in one class (correct me if I'm mistaken).
Now, as to your code: it's giving you an error that one of your methods takes a number of arguments, and you gave it a different number. Well, to me, it looks like you only need to pass one argument for this whole process: student_list_temp to student_list_updater(). Once again, I can't say for sure that this will solve your problems, based on the lack of code you posted, but this might work:
def student_list_updater(self, studentlist): #change list to studentlist,
self.StudentListDisplay.delete(0, END) #Python already has a list() method
for student in studentlist:
self.StudentListDisplay.insert(END, student)
def OnRemoveClick(self): #Remove student_list_updater from the args, it has no value
#self.student_list_updater = student_list_updater #this doesn't do anything
index = self.StudentListDisplay.curselection() #This part I can't really comment on
index = int(index[0]) #without knowing the contents of the
del student_list_temp[index] #Listbox and student_list_temp,
self.student_list_updater(student_list_temp) #but this should call student_list_updater()
#and update the Listbox if it's working
The last thing I want to point out is how you call OnRemoveClick() will probably change. If you're calling it from a Button, it would look like this:
self.btn = Button(self, text='GO', command=self.OnRemoveClick)
Note that you're not passing any arguments to it.
Hope that helps. You also might want to take a look at https://docs.python.org/2/tutorial/classes.html and https://docs.python.org/2/tutorial/modules.html to clear up any classes and functions questions you might have.
I want to envoke a method in my code in a supercass, to do some subclass- specific processing before continuing on. I come to python recently from C#... there, I'd probably use an interface. Here's the gist of it (as I picture it, but it's not working):
class superClass:
def do_specific_stuff(self): #To be implemented entirely by the subclass,
#but called from the superclass
pass
def do_general_stuff1(self):
#do misc
def do_general_stuff2(self):
#do more misc
def main_general_stuff(self):
do_general_stuff1()
do_specific_stuff()
do_general_stuff2()
I have a rather complicated implementation of this; this example is exactly what I need and far less painful to understand for a first- time viewer. Calling do_specific_stuff() at the moment gives me the error
'global name 'do_specific_stuff' is not defined.
When I add 'self' as in self.do_specific_stuff I get the error
'TypeError: do_specific_stuff() takes 0 positional arguments but 1 was given.' Any takers? Thanks in advance...
It needs to be
def main_general_stuff(self):
self.do_general_stuff1()
self.do_specific_stuff()
...
The problem is that you are missing the explicit reference to self: Python thinks you mean a global function without it. Note that there is no implicit this like in Java: You need to specify it.