class_docstr: This dataset describes a monthly count of the number of observed sunspots for
  just over 230 years (1749-1983).
  
  The units are a count and there are 2,820 observations. The source of the dataset is
  credited to Andrews & Herzberg (1985).
  
  References:
      .. [#1] Andrews, D. F. and Herzberg, A. M., "Data: A Collection of Problems from
          Many Fields for the Student and Research Worker,"
          New York: Springer-Verlag, 1985.
      .. [#2] https://stat.ethz.ch/R-manual/R-devel/library/datasets/html/sunspots.html
      .. [#3] https://r-data.pmagunia.com/dataset/r-dataset-package-datasets-sunspots
      .. [#4] Avishek Pal, PKS Prakash, "Practical Time Series Analysis"
          https://github.com/PacktPublishing/Practical-Time-Series-Analysis/
docstr: Prepares train and test dataframes.
  
  Returns:
  
      df (pd.DataFrame): The target time series pandas dataframe.
      schema (dict): The schema defining the fields used in the target and related
          dataframes.
code: def load_data(self):
      """
      Prepares train and test dataframes.
  
      Returns:
  
          df (pd.DataFrame): The target time series pandas dataframe.
          schema (dict): The schema defining the fields used in the target and related
              dataframes.
      """
      # ----------------------------------------------------------------------------------
      # df - The target time series pandas dataframe.
      # ----------------------------------------------------------------------------------
  
      df = pd.read_csv(self.data_file, header=0)
      df.columns = ["month", "sunspots"]
  
      # ----------------------------------------------------------------------------------
      # schema - The schema defining the fields used in the target and
      # related dataframes.
      # ----------------------------------------------------------------------------------
      schema = {}
      schema["name"] = "sunspots"
      schema[
          "description"
      ] = "monthly count of the number of observed sunspots for just over 230 years (1749-1983)"
      schema["timestamp"] = "month"
      schema["targets"] = ["sunspots"]
      schema["frequency"] = "M"
      schema["external_regressors"] = []
  
      return df, schema
  
file_path: AIX360/aix360/datasets/sunspots_dataset.py
imports: import os
  import math
  from io import StringIO
  import requests
  import pandas
label_desc: Use image node_id 3 for calling the SunspotDataset obj's underlying member method code with example usage: obj.load_data() and returns: df,  schema