CODEWITHSUNDEEP
pythonpython-3.x
Amy Fawcett
Amy Fawcett

Reputation: 107

Calling a method won't work because two positional arguments?

I'm really confused about how classes work, I've written this code but get the error message 

AttributeError: 'str' object has no attribute 'pLatin_converter'

but surely the object does have that attribute since it is of the class pigLatin_class?

class pigLatin_class (object):
    'class for converting plain text into pig latin'

    vowels = ["a", "e", "i", "o", "u", "A", "E", "I", "O", "U"]

    def __init__ (string):
        pig = ""
        movetoend = ""
        index = 0

    def pLatin_converter (string): 
        listeng = string.split()
        for word in listeng:
            length = len(word)
            movetoend = ""
            index = 0
            if word[0] not in vowels:
                for l in word:
                    if l not in vowels:
                        movetoend = movetoend + l
                        index = index + 1
                    else:
                        break
                pig = pig + " " + word[index:length] + movetoend + "ay"

            elif word[0] in vowels:
                pig = pig + " " + word[1:length] + "hay"
        print("pig latin is: " + pig)

    words = pigLatin_class()
    words = "Hi I'm Amy"
    words.pLatin_converter()

edit: okay i see my initial mistake, now if I input

words = pigLatin_class("Hi I'm Amy")
words.pLatin_converter()

it says I've given 2 positional arguments?

Upvotes: 0

Views: 104

Answers (2)

abarnert
abarnert

Reputation: 365707

surely the object does have that attribute since it is of the class "pigLatin_class"?

But it's not. You do create an instance of pigLatin_class, but then you immediately replace it with an instance of str:

words = pigLatin_class()
words = "Hi I'm Amy"

And str isn't pigLatin_class, and doesn't have a pLatin_converter method.

I think you wanted something like this:

words = pigLatin_class("Hi I'm Amy")
words.pLatin_converter()

But then you need to fix a few more bugs. Most crucially, the __init__ method of your class has to take a self parameter, as well as a string parameter, and then it needs to store things—including that string parameter value—on that self to be used later:

def __init__(self, string):
    self.string = string
    self.pig = ""
    self.movetoend = ""
    self.index = 0

And then, your methods will also take self and can use those attributes:

def pLatin_converter(self): 
    listeng = self.string.split()
    # etc.

You may have instead wanted something like this:

words = pigLatin_class()
words.pLatin_converter("Hi I'm Amy")

In that case, you won't be taking string as a second parameter in __init__ and storing it in self.string, you'll instead be taking it as a second parameter in pLatin_converter. Hopefully you know enough now to change it to work that way, and to understand the difference.

Upvotes: 3

trouselife
trouselife

Reputation: 969

You are passing the string 'Hi I'm Amy' to the pLatin_converter() method.

Instead, you need to do this:

class pigLatin_class (object):
    'class for converting plain text into pig latin'


    def __init__ (self, string):

        self.string = string
        self.vowels = ["a", "e", "i", "o", "u", "A", "E", "I", "O", "U"]

    def pLatin_converter(self):
        pig = ""
        movetoend = ""
        index = 0

        listeng = self.string.split()
        for word in listeng:
            length = len(word)
            movetoend = ""
            index = 0
            if word[0] not in self.vowels:
                for l in word:
                    if l not in self.vowels:
                        movetoend = movetoend + l
                        index = index + 1
                    else:
                        break
                pig = pig + " " + word[index:length] + movetoend + "ay"

            elif word[0] in self.vowels:
                pig = pig + " " + word[1:length] + "hay"
        print("pig latin is: " + pig)

words = pigLatin_class("Hi I'm Amy")

words.pLatin_converter()

You need to define variables that are class based with self.var_name and then you can access them throughout the class, by passing self as a method argument. In this case you pass the string to init() and save it in self.string variable, then you can access it when pLatin_converter() method is called.

Upvotes: 1

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