Python: Unable to call function within a seperate function? (undefined name 'getItemClassiness')

Question

For some reason the getClassiness Function does not work as it is not able to call the helper function getItemClassiness. Is there any reason this might be? Thanks!

class Classy(object):
    def __init__(self):
        self.items = []
    
    def addItem(self, item):
        self.items.append(item)
        
    def getItemClassiness(item):
        if item == "tophat":
            return 2
        if item == "bowtie":
            return 4
        if item == "monocle":
            return 5
        return 0
    
    
    def getClassiness(self):
        total = 0
        for item in self.items:
            x = getItemClassiness(item)
            total += x
        return total

# Test cases

me = Classy()

# Should be 0
print(me.getClassiness())


# Should be 2
me.addItem("tophat")
print(me.getClassiness())

me.addItem("bowtie")
me.addItem("jacket")
me.addItem("monocle")
print(me.getClassiness())
# Should be 11


me.addItem("bowtie\n")
print(me.getClassiness())
# Should be 15

You can use this class to represent how classy someone or something is. "Classy" is interchangable with "fancy". If you add fancy-looking items, you will increase your "classiness". Create a function in "Classy" that takes a string as input and adds it to the "items" list. Another method should calculate the "classiness" value based on the items. The following items have classiness points associated with them: "tophat" = 2 "bowtie" = 4 "monocle" = 5 Everything else has 0 points. Use the test cases below to guide you!

Sorry, I misread. There are two problems here: `getItemClassiness` should be a `@staticmethod`, and it needs to be explicitly looked up like `Classy.getItemClassiness` - yes, even within other `Classy` methods. Python does not have "implicit `this`" - hence all the explicit `self` parameters - so other methods of the class are not in the local scope. — Karl Knechtel, Jun 01 '22 at 02:25
See for example https://stackoverflow.com/questions/136097 and https://stackoverflow.com/questions/68645 . — Karl Knechtel, Jun 01 '22 at 02:26

score 1 · Answer 1 · answered Jan 18 '23 at 16:22

 class Classy(object):
def __init__(self):
    self.items = []

def addItem(self, string):
    self.items.append(string)
    
def getClassiness(self):
    sum = 0
    for item in self.items:
        if (item == "tophat"):
            sum += 2
        elif (item == "bowtie"):
            sum += 4
        elif (item == "monocle"):
            sum += 5
        else:
            sum += 0
    return sum

Excited Electron · Answer 2 · 2022-06-01T02:31:02.230

0

In line 21 call for a class method is made without using the self keyword.

 x = self.getItemClassiness(item)

Similarly on line 8 in self keyword is required with as parameter for function definition of getItemClassiness

def getItemClassiness(self, item):

edited Jun 01 '22 at 02:31

answered Jun 01 '22 at 02:22

Excited Electron

1
2

Thanks! I tried that before but kept getting this error, Im not sure what is wrong? x = self.getItemClassiness(item) TypeError: Classy.getItemClassiness() takes 1 positional argument but 2 were given – SDC123 Jun 01 '22 at 02:29
you can also create the function outside the class and use it without referencing to object. – Excited Electron Jun 01 '22 at 02:32
Ok, so the x = self.getItemClassiness(item) is correct, however I just needed to add an @staticmethod above the getItemClassiness() method, and now it works! Thank you for your help! – SDC123 Jun 01 '22 at 02:32
@SDC123 It helps to think of `self.getItemClassiness(item)` as `Classy.getItemClassiness(self, item)`. – Edward Ji Jun 01 '22 at 02:35
Ok, that makes sense. I guess I was just kinda confused as self is not in java. I appreciate the help! – SDC123 Jun 01 '22 at 02:39

score 0 · Accepted Answer · answered Jun 01 '22 at 02:25

You should declare getItemClassiness as a static method because it doesn't require a specific instance. Then you can call the function as you would an instance method.

    @staticmethod
    def getItemClassiness(item):
        ...
    
    
    def getClassiness(self):
        ...
        for item in self.items:
            x = self.getItemClassiness(item)

But still it won't give you 15 for the last test case, because "bowtie" != "bowtie\n". If you intend to ignore white space at the start or the end of the string, use str.strip().

Works! Thank you so much. I am used to Java and just started with python, didn't know about the @staticmethod. I appreciate ur help! — SDC123, Jun 01 '22 at 02:32

score 0 · Answer 4 · edited Dec 06 '22 at 20:07

Here is what I did using Static Method. Got the right output in Test Cases.

class Classy(object):
    def __init__(self):
        self.items = []
        
    def addItem(self, item):
        self.items.append(item)
        
    @staticmethod
    def getItemClassiness(item):
        if item == "tophat":
            return 2
        if item == "bowtie":
            return 4
        if item == "monocle":
            return 5
        return 0
    
    
    def getClassiness(self):
        total = 0
        for item in self.items:
            x = self.getItemClassiness(item)
            total += x
        return total

Python: Unable to call function within a seperate function? (undefined name 'getItemClassiness')

4 Answers4