CODEWITHSUNDEEP
pythonpandasdataframeclasspython-dataclasses
Flynn O'Connell
Flynn O'Connell

Reputation: 49

Manipulating DataFrame with custom dataclass methods

I have upwards of 4000 lines of code that analyze, manipulate, compare and plot 2 huge .csv documents. For readability and future publication, I'd like to convert to object-oriented classes. I convert them to pd.DataFrames:

my_data1 = pd.DataFrame(np.random.randn(100, 9), columns=list('123456789'))
my_data2 = pd.DataFrame(np.random.randn(100, 4), columns=list('ABCD'))

I have functions that compare various aspects of each of the datasets and functions that only use the datasets individually. I want to convert this structure into a dataclass with methods for each dataframe.

I can't manipulate these dataframes through my class functions. I keep getting NameError: name 'self' is not defined. Here's my dataclass structure:

@dataclass
class Data:
    ser = pd.DataFrame 

    # def __post_init__(self):
    #     self.ser = self.clean()

    def clean(self, ser):
        acceptcols = np.where(ser.loc[0, :] == '2')[0]
        data = ser.iloc[:, np.insert(acceptcols, 0, 0)]
        data = ser.drop(0)
        data = ser.rename(columns={'': 'Time(s)'})
        data = ser.astype(float)
        data = ser.reset_index(drop=True)
        data.columns = [column.replace('1', '')
                        for column in ser.columns]

        return data


my_data1 = pd.DataFrame(np.random.randn(100, 9), columns=list('123456789'))
my_data2 = pd.DataFrame(np.random.randn(100, 4), columns=list('ABCD'))

# Attempt 1
new_data1 = Data.clean(my_data1) # Parameter "ser" unfilled 
# Attempt 2
new_data1 = Data.clean(ser=my_data1) # Parameter "self" unfilled 
# Attempt 3
new_data1 = Data.clean(self, my_data1) # Unresolved reference "self"

I have tried various forms of defining def clean(self and other stuff) but I think I just don't understand classes or class structure enough. Documentation on classes and dataclasses always use very rudimentary examples, I've tried cut/pasting a template to no avail. What am I missing?

Upvotes: 1

Views: 1261

Answers (1)

Raymond Kwok
Raymond Kwok

Reputation: 2541

you can first get an instance x of the class Data.

x = Data()

# Attempt 1
new_data1 = x.clean(my_data1) # Parameter "ser" unfilled 
# Attempt 2
new_data1 = x.clean(ser=my_data1) # Parameter "self" unfilled

If I were you I would not use a class this way, I would instead just define the following function

def clean(ser):
        acceptcols = np.where(ser.loc[0, :] == '2')[0]
        data = ser.iloc[:, np.insert(acceptcols, 0, 0)]
        data = ser.drop(0)
        data = ser.rename(columns={'': 'Time(s)'})
        data = ser.astype(float)
        data = ser.reset_index(drop=True)
        data.columns = [column.replace('1', '')
                        for column in ser.columns]

        return data

and call it directly.

Also, in your clean(), each modification is based on ser which is the input, but not the last modification. This is a problem, isn't this?

Upvotes: 2

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