Develop Reference

Getting the TypeError: 'list' object is not callable in Python

class Student:
def __init__(self,first,last,id):
self._first_name = first
self._last_name = last
self._id_number = id
self._enrolled_in = []
def enroll_in_course(self,course):
self._enrolled_in.append(course)
return self._enrolled_in()
s1 = Student("kathy","lor","323232")
s1.enroll_in_course("hello")
print(s1._enrolled_in)
In the code above, i am getting the error as:
Traceback (most recent call last):
File "main.py", line 14, in
s1.enroll_in_course("hello") File "main.py", line 10, in enroll_in_course
return self._enrolled_in()
TypeError: 'list' object is not callable
I am trying to solve the error, but unable to do so. Can anybody help me here.

You have defined self._enrolled_in but you're adding it to self.enrolled_in
Missed the underscore (self._enrolled_in.append)

You have called the attribute _enrolled_in in your __init__() method. In the enroll_in_course() method you're trying to append to enrolled_in which does not exist. So try by adding the underscore in front.

You are missing an _ in the appended statement. You should write self._enrolled_in.append(course) on your enroll_in_course method.

Attribute Error in python. Object has no attribute

This code is part of a bigger program that uses the google Sheets API to get data from a cloud database (not really relevant, but a bit of context never hurt!)
I have this black of code in one python file named 'oop.py'
class SetupClassroom:
def __init__(self, arraynumber='undefined', tkroot='undefined'):
self.arraynumber = arraynumber
self.tkroot = tkroot
def setarraynumber(self, number):
from GUI_Stage_3 import showclassroom
self.arraynumber = number
print ('set array number:', number)
showclassroom()
def settkroot(self, tkrootinput):
self.tkroot = tkrootinput
self.tkroot has been assigned by another part of the code. This bit works, as I have already tested that it is being assigned, however, when I call 'self.tkroot' in another another file like this
def showclassroom():
from oop import SetupClassroom
username = current_user.username
classnumber = getnumberofuserclassrooms(username)
if SetupClassroom.arraynumber > classnumber:
errorwindow('you are not enrolled in that many classrooms!')
else:
classtoget = SetupClassroom.arraynumber
print('classtoget:', classtoget)
root = SetupClassroom.tkroot
name_label = Label(root, text=classtoget)
getclassroom(username, classtoget)
SetupClassroom = SetupClassroom
I get this error
Exception in Tkinter callback
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/tkinter/__init__.py", line 1705, in __call__
return self.func(*args)
File "/Users/jonathansalmon/PycharmProjects/Coursework_GUI/GUI_Stage2_better.py", line 176, in <lambda>
l0 = ttk.Button(teacher_root, text=button0text, command=lambda: (SetupClassroom.setarraynumber(SetupClassroom, number=button0text), SetupClassroom.settkroot(SetupClassroom, 'teacher_root')))
File "/Users/jonathansalmon/PycharmProjects/Coursework_GUI/oop.py", line 99, in setarraynumber
showclassroom()
File "/Users/jonathansalmon/PycharmProjects/Coursework_GUI/GUI_Stage_3.py", line 29, in showclassroom
root = SetupClassroom.tkroot
AttributeError: type object 'SetupClassroom' has no attribute 'tkroot'
I tried setting it up in the python console and it worked, so I have no idea what the problem is.
If anyone could help, it would be very much appreciated
Thanks!
John

You should create an instance of class, it will create the attribute in __init__, self.tkroot is the attribute of instance not class:
setupClassroom = SetupClassroom()
print(setupClassroom.tkroot)
Hope that will help you.

zipline run_pipeline and positional arguments

I'm using Zipline-1.1.1, Python3.4.6 to create a dynamic stock selector as follows:
from zipline.pipeline import Pipeline, engine
from zipline.pipeline.factors import AverageDollarVolume, Returns
def make_pipeline():
dollar_volume = AverageDollarVolume(window_length=1)
high_dollar_volume = dollar_volume.percentile_between(N, 100)
recent_returns = Returns(window_length=N, mask=high_dollar_volume)
low_returns = recent_returns.percentile_between(0, n)
high_returns = recent_returns.percentile_between(N, 100)
pipe_columns = {
'low_returns': low_returns,
'high_returns': high_returns,
'recent_returns': recent_returns,
'dollar_volume': dollar_volume
}
pipe_screen = (low_returns | high_returns)
pipe = Pipeline(columns=pipe_columns, screen=pipe_screen)
return pipe
I initialize a pipeline object with:
my_pipe = make_pipeline()
But when I try to populate the Pipeline, it fails with:
result = engine.PipelineEngine.run_pipeline(my_pipe, '2017-07-10', '2017-07-11')
Traceback (most recent call last):
File "<input>", line 1, in <module>
result = engine.PipelineEngine.run_pipeline(my_pipe, '2017-07-10', '2017-07-11')
TypeError: run_pipeline() missing 1 required positional argument: 'end_date'
I can't figure out what is wrong, any help is much appreciated.

If I understand correctly, you're using this library.
As far as I can see from that code, to be able to use run_pipeline method you have to instantiate on of pipeline engines before, e.g. SimplePipelineEngine. You need that because PipelineEngine is a class, even abstract class, not an object.
So you have to create an object of SimplePipelineEngine class and then call run_pipeline on it. You can do it this way:
your_engine = SimplePipelineEngine(get_loader=your_loader, calendar=your_calendar, asset_finder=your_asset_finder)
your_eninge.run_pipeline(my_pipe, '2017-07-10', '2017-07-11')
Of course you have to create your_loader etc. first.
Here is example of SimplePipelineEngine usage. I hope it will help.

Python unittesting initiate values

Sorry if this question is stupid. I created an unittest class which needs to take given inputs and outputs from outside. Thus, I guess these values should be initiated. However, I met some errors in the following code:
CODE:
import unittest
from StringIO import StringIO
##########Inputs and outputs from outside#######
a=[1,2]
b=[2,3]
out=[3,4]
####################################
def func1(a,b):
return a+b
class MyTestCase(unittest.TestCase):
def __init__(self,a,b,out):
self.a=a
self.b=b
self.out=out
def testMsed(self):
for i in range(self.tot_iter):
print i
fun = func1(self.a[i],self.b[i])
value = self.out[i]
testFailureMessage = "Test of function name: %s iteration: %i expected: %i != calculated: %i" % ("func1",i,value,fun)
self.assertEqual(round(fun,3),round(value,3),testFailureMessage)
if __name__ == '__main__':
f = MyTestCase(a,b,out)
from pprint import pprint
stream = StringIO()
runner = unittest.TextTestRunner(stream=stream, verbosity=2)
result = runner.run(unittest.makeSuite(MyTestCase(a,b,out)))
print 'Tests run', result.testsRun
However, I got the following error
Traceback (most recent call last):
File "C:testing.py", line 33, in <module>
result = runner.run(unittest.makeSuite(MyTestCase(a,b,out)))
File "C:\Python27\lib\unittest\loader.py", line 310, in makeSuite
return _makeLoader(prefix, sortUsing, suiteClass).loadTestsFromTestCase(testCaseClass)
File "C:\Python27\lib\unittest\loader.py", line 50, in loadTestsFromTestCase
if issubclass(testCaseClass, suite.TestSuite):
TypeError: issubclass() arg 1 must be a class
Can anyone give me some suggestions? Thanks!

The root of the problem is this line,
result = runner.run(unittest.makeSuite(MyTestCase(a,b,out)))
unittest.makeSuite expects a class, not an instance of a class. So just MyTestCase, not MyTestCase(a, b, out). This means that you can't pass parameters to your test case in the manner you are attempting to. You should probably move the code from init to a setUp function. Either access a, b, and out as globals inside setUp or take a look at this link for information regarding passing parameters to a unit test.
By the way, here is the source file within python where the problem originated. Might be informative to read.

Variable not the same type in two different functions

I have two functions which print into an excel file. THe only input is the file name. Here is the code:
#excelpy
import excelpy
#Tinker
from Tkinter import *
from tkSimpleDialog import *
from tkFileDialog import *
Function Mode1
def Mode1(full_name):
print full_name
print type(full_name)
testwbook = excelpy.workbook(full_name)
testwbook.show()
testwbook.set_cell((1,1),'TEST1', fontColor='red')
testwbook.set_range(2,1,['Number','Name'])
m1 = testwbook.save(full_name)
testwbook.close()
return m1
Function Mode2
def Mode2(full_name):
print full_name
print type(full_name)
testwbook = excelpy.workbook(full_name)
testwbook.show()
testwbook.set_cell((1,1),'TEST2', fontColor='red')
testwbook.set_range(2,1,['Number','Name'])
m2 = testwbook.save(full_name)
testwbook.close()
return m2
Main
root = Tk()
d = str(asksaveasfilename(parent=root,filetypes=[('Excel','*.xls')],title="Save report as..."))
d = d + '.xls'
d = d.replace('/','\\')
root.destroy()
Mode1(d)
Mode2(d)
And once in a while I get the following error:
Traceback (most recent call last):
File "T:\TEST\testpy.py", line 2035, in <module>
Mode2(d)
File ""T:\TEST\testpy.py"", line 1381, in Mode2
print type(full_name)
TypeError: 'str' object is not callable
Any idea why is this happening? How can I prevent it?

The only function call in the line you get the error is a call to the built-in function type(), so the only explanation for your error message is that you overwrote the built-in name type by a global name type pointing to a string object. Try adding
print type
before
print type(full_name)

It looks like somewhere you're setting a (global) variable named type to a string, thus overwriting the built-in type function.
Try searching your code for type = to see what turns up.
Understandably, Python would then throw that exception when you tried to call type (strings can't be "called").