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Is there a way to grab list attributes that have been initialized using self and append data to them in Python?

I have a class in Python that initializes the attributes of an environment. I am attempting to grab the topographyRegistry attribute list of my Environment class in a separate function, which when called, should take in the parameters of 'self' and the topography to be added. When this function is called, it should simply take an argument such as addTopographyToEnvironment(self, "Mountains") and append it to the topographyRegistry of the Environment class.
When implementing what I mentioned above, I ran into an error regarding the 'self' method not being defined. Hence, whenever I call the above line, it gives me:
print (Environment.addTopographyToEnvironment(self, "Mountains"))
^^^^
NameError: name 'self' is not defined
This leads me to believe that I am unaware of and missing a step in my implementation, but I am unsure of what that is exactly.
Here is the relevant code:
class EnvironmentInfo:
def __init__(self, perceivableFood, perceivableCreatures, regionTopography, lightVisibility):
self.perceivableFood = perceivableFood
self.perceivableCreatures = perceivableCreatures
self.regionTopography = regionTopography
self.lightVisibility = lightVisibility
class Environment:
def __init__(self, creatureRegistry, foodRegistry, topographyRegistery, lightVisibility):
logging.info("Creating new environment")
self.creatureRegistry = []
self.foodRegistry = []
self.topographyRegistery = []
self.lightVisibility = True
def displayEnvironment():
creatureRegistry = []
foodRegistry = []
topographyRegistery = ['Grasslands']
lightVisibility = True
print (f"Creatures: {creatureRegistry} Food Available: {foodRegistry} Topography: {topographyRegistery} Contains Light: {lightVisibility}")
def addTopographyToEnvironment(self, topographyRegistery):
logging.info(
f"Registering {topographyRegistery} as a region in the Environment")
self.topographyRegistery.append(topographyRegistery)
def getRegisteredEnvironment(self):
return self.topographyRegistry
if __name__ == "__main__":
print (Environment.displayEnvironment()) #Display hardcoded attributes
print (Environment.addTopographyToEnvironment(self, "Mountains"))#NameError
print (Environment.getRegisteredEnvironment(self)) #NameError
What am I doing wrong or not understanding when using 'self'?
Edit: In regard to omitting 'self' from the print statement, it still gives me an error indicating a TypeError:
print (Environment.addTopographyToEnvironment("Mountains"))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: Environment.addTopographyToEnvironment() missing 1 required positional argument: 'topographyRegistery'

Comments
Despite having def getRegisteredEnvironment(self): it wasn't indented, so it's not recognized as a class method.
self is a keyword used in conjunction with classes (class methods or attributes) - not functions. self is implied to be the instantiated object (eg a = Environment(...) -> self would refer to a) or the module's (I can't think of the proper term) class.
You didn't have your addTopographyToEnvironment class method defined.
In terms of your Environment class, you aren't using the variables you are passing to the class, so I made that change as well - I don't know if that was intentional or not.
As per your comment from the other answer, if you had def my_class_method(self) and you try to invoke it through an object with additional parameters, like so a = my_object(); a.my_class_method("Mountains"), you should get an error of the sorts, "2 positional arguments passed, expected 1.".
Your main problem is that you are doing Environment.class_method() and not creating an object from the class. Do a = Environment(whatever arguments here) to create an object from the class, then do a.addTopographyToEnvironment("Mountains") to do what you were going to do with "Mountains" and that object. What you have currently may be right, its just is missing the proper implementation, but the below article does a great job explaining the differences between all of them (Class Methods vs Static Methods vs Instance Methods), and is definitely worth the read.
class EnvironmentInfo:
def __init__(self, perceivableFood, perceivableCreatures, regionTopography, lightVisibility):
self.perceivableFood = perceivableFood
self.perceivableCreatures = perceivableCreatures
self.regionTopography = regionTopography
self.lightVisibility = lightVisibility
class Environment:
def __init__(self, creatureRegistry, foodRegistry, topographyRegistery, lightVisibility):
logging.info("Creating new environment")
self.creatureRegistry = creatureRegistry
self.foodRegistry = foodRegistry
self.topographyRegistery = topographyRegistery
self.lightVisibility = lightVisibility
def displayEnvironment(self):
creatureRegistry = []
foodRegistry = []
topographyRegistery = ['Grasslands']
lightVisibility = True
print (f"Creatures: {creatureRegistry} Food Available: {foodRegistry} Topography: {topographyRegistery} Contains Light: {lightVisibility}")
def addTopographyToEnvironment(self, environment):
return "Whatever this is supposed to return." + environment
def getRegisteredEnvironment(self):
return self.topographyRegistry
if __name__ == "__main__":
print (Environment.displayEnvironment()) #Display hardcoded attributes
print (Environment.addTopographyToEnvironment("Mountains"))#NameError
print (Environment.getRegisteredEnvironment()) #NameError
Object Instantiation In Python
With all that out of the way, I will answer the question as is posed, "Is there a way to grab list attributes that have been initialized using self and append data to them in Python?". I am assuming you mean the contents of the list and not the attributes of it, the attributes would be "got" or at least printed with dir()
As a simple example:
class MyClass:
def __init__(self, my_list):
self.my_list = my_list
if __name__ == "__main__":
a = MyClass([1, 2, 3, 4, 5])
print(a.my_list)
# will print [1, 2, 3, 4, 5]
a.my_list.append(6)
print(a.my_list)
# will print [1, 2, 3, 4, 5, 6]
print(dir(a.my_list))
# will print all object methods and object attributes for the list associated with object "a".
Sub Classing In Python
Given what you have above, it looks like you should be using method sub classing - this is done with the keyword super. From what I can guess, it would look like you'd implement that kind of like this:
class EnvironmentInfo:
def __init__(self, perceivableFood, perceivableCreatures, regionTopography, lightVisibility):
self.perceivableFood = perceivableFood
self.perceivableCreatures = perceivableCreatures
self.regionTopography = regionTopography
self.lightVisibility = lightVisibility
class Environment(EnvironmentInfo):
def __init__(self, creatureRegistry, foodRegistry, topographyRegistery, lightVisibility, someOtherThingAvailableToEnvironmentButNotEnvironmentInfo):
logging.info("Creating new environment")
super.__init__(foodRegistry, creatureRegistry, topographyRegistery, lightVisibility)
self.my_var1 = someOtherThingAvailableToEnvironmentButNotEnvironmentInfo
def displayEnvironment(self):
creatureRegistry = []
foodRegistry = []
topographyRegistery = ['Grasslands']
lightVisibility = True
print (f"Creatures: {creatureRegistry} Food Available: {foodRegistry} Topography: {topographyRegistery} Contains Light: {lightVisibility}")
def addTopographyToEnvironment(self, environment):
return "Whatever this is supposed to return." + environment
def getRegisteredEnvironment(self):
return self.topographyRegistry
def methodAvailableToSubClassButNotSuper(self)
return self.my_var1
if __name__ == "__main__":
a = Environment([], [], [], True, "Only accessible to the sub class")
print(a.methodAvailableToSubClassButNotSuper())
as the article describes when talking about super(), methods and attributes from the super class are available to the sub class.
Extra Resources
Class Methods vs Static Methods vs Instance Methods - "Difference #2: Method Defination" gives an example that would be helpful I think.
What is sub classing in Python? - Just glanced at it; probably an okay read.

Self represents the instance of the class and you don't have access to it outside of the class, by the way when you are calling object methods of a class you don't need to pass self cause it automatically be passed to the method you just need to pass the parameters after self so if you want to call an object method like addTopographyToEnvironment(self, newVal) you should do it like:
Environment.addTopographyToEnvironment("Mountains")
and it should work fine

How to declare the __init__ variables that is not necessarily required

class Gathering(object):
def __init__(self, date, spent1, spent2, spent3, spent4):
"""Return a gathering object whose date is declared """
self.date = date
self.spent1 = spent1
self.spent2 = spent2
self.spent3 = spent3
self.spent4 = spent4
self.spent_total = spent1+spent2+spent3+spent4
def per_person(self):
return self.spent_total/3
I had made short script that I can easily calculate the portion of one person when me and my friend had some gatehring. We usally move the spots and spent different amount of money, but how many places we visit that night is always different.
So I"d like to make spent1,2,3,4 variables not necessarily required, how can I do that?

You may use a variable number of arguments:
class Gathering(object):
def __init__(self, date, *args):
"""Return a gathering object whose date is declared """
self.date = date
self.spent = args
self.spent_total = sum(args, 0)
def per_person(self):
return self.spent_total / 3.0
sent contains a tuple of values. You can use your class like:
g1 = Gathering(date1, 1, 2, 3)
g2 = Gathering(date2, 2, 3)
and so on.

When a list is used as a property in Python, the setter isn't actually called when you change an individual value in the list

Essentially what I'm trying to do is create a class that represents a robot arm.
Inside of the arm there's a list that represents the joints, and my hope was that whenever those joints are 'set', it would transmit the values to a secondary microcontroller that controls the PWM signals that physically set the servos.
My problem is that when I only want to move 1 joint, but leave the others to be the same, I can't just say arm.joints[0] = 5, because it sets the value but doesn't actually call the setter.
Is there a better way to structure this?
class RobotArm(object):
"""An object that resembles a robotic arm with n joints"""
def __init__(self):
# Empty list of zeros representing each joint
self.joints = [0]*5
#property
def joints(self):
return self.__joints
#joints.setter
def joints(self, vals):
print "setting values"
self.__joints = vals
self.serial_transmission(vals)

One solution is to use a custom list:
class Joints(list):
"""A custom list owned by another object. The owner should have
a before_set_joints() method and an after_set_joints() method.
"""
def __init__(self, owner, *args):
self.owner = owner
list.__init__(self, *args)
def __setitem__(self, key, value):
self.owner.before_set_joints()
list.__setitem__(self, key, value)
self.owner.after_set_joints()
# Define the onwer's methods cooperatively
class RobotArm(object):
def __init__(self):
self.__joints = Joints(self, [0] * 5) # make self the owner
def before_set_joints(self):
print 'setting values'
def after_set_joints(self):
self.serial_transmission(self.joints) # note a slight change here
The property definition can be just as before, but the setter needs to be modified:
#joints.setter
def joints(self, vals):
self.before_set_joints()
self.__joints = Joints(self, vals)
self.after_set_joints()
Demo (I defined serial_transmission to simply print "serial_transmission" and the list content):
>>> arm = RobotArm()
>>> print(arm.joints)
[0, 0, 0, 0, 0]
>>> arm.joints = [1] * 5
setting joints
serial_transmission [1, 1, 1, 1, 1]
>>> arm.joints[0] = 5
setting joints
serial_transmission [5, 1, 1, 1, 1]

Python: referencing class object list of lists

I am fairly new to python. I have tried to define a class, I then want to create an instance from a file, then refer to specific pieces of it, but cannot seem to. This is Python 3.3.0
Here's the class....
class Teams():
def __init__(self, ID = None, Team = None, R = None, W = None, L = None):
self._items = [ [] for i in range(5) ]
self.Count = 0
def addTeam(self, ID, Team, R=None, W = 0, L = 0):
self._items[0].append(ID)
self._items[1].append(Team)
self._items[2].append(R)
self._items[3].append(W)
self._items[4].append(L)
self.Count += 1
def addTeamsFromFile(self, filename):
inputFile = open(filename, 'r')
for line in inputFile:
words = line.split(',')
self.addTeam(words[0], words[1], words[2], words[3], words[4])
def __len__(self):
return self.Count
Here's the code in Main
startFileName = 'file_test.txt'
filename = startFileName
###########
myTestData = Teams()
myTestData.addTeamsFromFile(startFileName)
sample data in file
100,AAAA,106,5,0
200,BBBB,88,3,2
300,CCCC,45,1,4
400,DDDD,67,3,2
500,EEEE,90,4,1
I think I am good to here (not 100% sure), but now how do I reference this data to see... am i not creating the class correctly? How do I see if one instance is larger than another...
ie, myTestData[2][2] > myTestData[3][2] <----- this is where I get confused, as this doesn't work

Why don't you create a Team class like this :
class Team():
def __init__(self, ID, Team, R=None, W = 0, L = 0)
# set up fields here
Then in Teams
class Teams():
def __init__(self):
self._teams = []
def addTeam (self, ID, Team, R=None, W = 0, L = 0)
team = Team (ID, Team, R=None, W = 0, L = 0)
self._teams.append (team)
Now If i got it right you want to overwrite the > operator's behaviour.
To do that overload __gt__(self, other) [link]
So it will be
class Team ():
# init code from above for Team
def __gt__ (self, otherTeam):
return self.ID > otherTeam.ID # for example
Also be sure to convert those strings to numbers because you compare strings not numbers. Use int function for that.

The immediate problem you're running into is that your code to access the team data doesn't account for your myTestData value being an object rather than a list. You can fix it by doing:
myTestData._items[2][2] > myTestData._items[3][2]
Though, if you plan on doing that much, I'd suggest renaming _items to something that's obviously supposed to be public. You might also want to make the addTeamsFromFile method convert some of the values it reads to integers (rather than leaving them as strings) before passing them to the addTeam method.
An alternative would be to make your Teams class support direct member access. You can do that by creating a method named __getitem__ (and __setitem__ if you want to be able to assign values directly). Something like:
def __getitem__(self, index):
return self._items[index]
#Aleksandar's answer about making a class for the team data items is also a good one. In fact, it might be more useful to have a class for the individual teams than it is to have a class containing several. You could replace the Teams class with a list of Team instances. It depends on what you're going to be doing with it I guess.

Interfering objects (or something less sinister?)

I have created a word object, which consists of just two methods, and takes just two parameters. In spite of this apparent simplicity it is behaving in a way that's beyond my comprehension: if I create two instances of the same object, with the same first argument ("dissembling" in this case) the second instance somehow interferes with the first. Printing the instances reveals that they are indeed separate, so why are the interacting in this way?
# Example tested with Python 2.7.3
from collections import namedtuple
DefinitionTuple = namedtuple("Definition", "word word_id text pos")
class Word(object):
def __init__(self, word, defs=None):
""""""
self.definitions = []
self.word = word
if defs != None:
for each in defs:
try:
each.pos
if each.word.lower() == self.word.lower():
self.definitions.append(each)
except AttributeError:
raise AttributeError("Definitions must be named tuples")
self.orderDefinitions()
def orderDefinitions(self):
""""""
ordered = sorted(self.definitions, key=lambda definition: definition.pos)
for i,each in enumerate(ordered):
each.pos = (i+1)
self.definitions = ordered
class Definition(object):
""""""
def __init__(self, definition):
"""Incoming arg is a single namedtuple"""
self.word = definition.word
self.word_id = definition.word_id
self.text = definition.text
self.pos = definition.pos
if __name__ == "__main__":
nt1 = DefinitionTuple("dissemble", 5, "text_string_a", 1)
nt2 = DefinitionTuple("dissemble", 5, "text_string_b)", 2)
nt3 = DefinitionTuple("dissemble", 5, "text_string_c", 3)
# Definiton objects
def_1 = Definition(nt1)
def_2 = Definition(nt2)
def_3 = Definition(nt3)
dissemble = Word("dissemble", [def_1, def_2, def_3])
print "first printing: "
for each in dissemble.definitions:
print each.pos, each.text
# create a new instance of Word ...
a_separate_instance = Word("dissemble", [def_3])
# ... and now the 'pos' ordering of my first instance is messed up!
print "\nnow note how numbers differ compared with first printing:"
for each in dissemble.definitions:
print each.pos, each.text

You create a new instance of Word, but you reuse the same instance of def_3:
a_separate_instance = Word("dissemble", [def_3])
which is stateful. If we look inside using vars:
print vars(def_3)
# create a new instance of Word ...
a_separate_instance = Word("dissemble", [def_3])
print vars(def_3)
We see
{'text': 'text_string_c', 'word': 'dissemble', 'pos': 3, 'word_id': 5}
{'text': 'text_string_c', 'word': 'dissemble', 'pos': 1, 'word_id': 5}
due to orderDefinitions.

In your orderDefinitions method, you are modifying the pos attribute of your Definition objects:
each.pos = (i+1)
So when you call orderDefinitions a second time, you will be doing def_3.pos = 1.
But, dissemble holds a reference to this def_3 object, whose pos attribute has now changed, hence your issue.