old_contents: import pandas as pd
  
  print('\nKNN\n---')
  d = {'X1': [ 0,   2,   0,   0,  -1,   1 ],
       'X2': [ 3,   0,   1,   1,   0,   1 ],
       'X3': [ 0,   0,   3,   2,   1,   1 ],
       'Y':  ['R', 'R', 'R', 'G', 'G', 'R']}
  df = pd.DataFrame(data = d)
  df = df.assign(dist = (df.X1**2 + df.X2**2 + df.X3**2)**(0.5))
  df = df.sort_values(by='dist')
  print(df)
  print('K=1 =>', df.head(1).Y.to_numpy()[0])
  print('K=3 =>', df.head(3).groupby('Y').count().sort_values(by='dist', # arbitrary
      ascending=False).index.values[0])
  
  print('\nCollege.csv\n-----------')
  df = pd.read_csv('College.csv')
  print(df)
  
new_contents: import matplotlib.pyplot as plt
  import pandas as pd
  
  print('\nKNN\n---')
  d = {'X1': [ 0,   2,   0,   0,  -1,   1 ],
       'X2': [ 3,   0,   1,   1,   0,   1 ],
       'X3': [ 0,   0,   3,   2,   1,   1 ],
       'Y':  ['R', 'R', 'R', 'G', 'G', 'R']}
  df = pd.DataFrame(data = d)
  df = df.assign(dist = (df.X1**2 + df.X2**2 + df.X3**2)**(0.5))
  df = df.sort_values(by='dist')
  print(df)
  print('K=1 =>', df.head(1).Y.to_numpy()[0])
  print('K=3 =>', df.head(3).groupby('Y').count().sort_values(by='dist', # arbitrary
      ascending=False).index.values[0])
  
  print('\nCollege.csv\n-----------')
  df = pd.read_csv('College.csv')
  df.rename(columns={'Unnamed: 0': 'Name'}, inplace=True)
  df.set_index('Name', inplace=True)
  print(df.describe())
  fig = plt.figure()
  gs = fig.add_gridspec(10, 10)
  for r in range(10):
      for c in range(10):
          axes = fig.add_subplot(gs[r, c])
          axes.xaxis.set_visible(False)
          axes.yaxis.set_visible(False)
          if r == c:
              axes.annotate(df.columns.values[r], (0.5, 0.5),
                  xycoords='axes fraction', ha='center', va='center')
          else:
              df.plot.scatter(x=r, y=c, ax=axes)
  plt.show()
  
subject: Add scatterplot matrix for college.csv.