How can function call another functions in same class python

Question

I want to create a class that includes some functions, that one of them call another one in class, something like that:

import pandas as pd


class Prep:
    def __init__(self, data):
        self.data = data

    def slicing(self):
        sliceInput = self.data.iloc[:, 1:8]
        sliceTarget = self.data.iloc[:, 8]
        return sliceInput, sliceTarget

    def convert(self):
        convertInput = sliceInput.to_numpy(float)
        convertTarget = sliceTarget.to_numpy(int)
        return convertInput, convertTarget

if __name__ == "__main__":
    data_frame = pd.read_csv('data_manual.csv', sep=';')

    tes = Prep(data_frame)
    print(tes.convert())

i got error like this NameError: name 'sliceInput' is not defined

how to call convertInput and convertTarget in function why I get an error, I don't understand at all.

Answer 1

You need to add sliceInput, sliceTarget = self.slicing() in covert

import pandas as pd


class Prep:
    def __init__(self, data):
        self.data = data

    def slicing(self):
        sliceInput = self.data.iloc[:, 1:8]
        sliceTarget = self.data.iloc[:, 8]

        return sliceInput, sliceTarget

    def convert(self):
        sliceInput, sliceTarget = self.slicing()
        convertInput = sliceInput.to_numpy(float)
        convertTarget = sliceTarget.to_numpy(int)
        return convertInput, convertTarget

if __name__ == "__main__":
    data_frame = pd.read_csv('data_manual.csv', sep=';')

    tes = Prep(data_frame)
    print(tes.convert())

Answer 2

Just add self to the defined attributes. Also, because data is immutable after you have instantiated a Prep object, it would be better for performance if you just initialize the slice variables once in the __init__() method.

import pandas as pd


class Prep:
    def __init__(self, data):
        self.data = data
        self.sliceInput = data.iloc[:, 1:8]
        self.sliceTarget = data.iloc[:, 8]

    def slicing(self):
        return self.sliceInput, self.sliceTarget


    def convert(self):
        convertInput = self.sliceInput.to_numpy(float)
        convertTarget = self.sliceTarget.to_numpy(int)
        return convertInput, convertTarget

if __name__ == "__main__":
    data_frame = pd.read_csv('data_manual.csv', sep=';')

    tes = Prep(data_frame)
    print(tes.convert())