text: import pandas as pd
  from string import ascii_lowercase
  import numpy as np
  
  df = pd.DataFrame(np.random.randn(50, 4), columns=list('ABCD'))
  
  def abc_df(data):
      df = pd.DataFrame(data=data,    # values
                        index=list(ascii_lowercase[:data.shape[0]]),    # 1st column as index
                        columns=list(ascii_lowercase[:data.shape[1]]))
      return df
  
  def last_col_median(df):
      if np.issubdtype(df.iloc[:,-1].dtype, np.number):
          return df.iloc[:,-1].median(axis=0)
      else:
          return None
  
  # def last_col_median(df):
  #     last_col = df.iloc[:,-1]
  #     try:
  #         answer = last_col.median()
  #     except TypeError:
  #         answer = None
  #     return answer
  
  # last_col_median(df)
  # https://docs.python.org/2/tutorial/errors.html
  
  def most_common_index(df):
      return max(df.index.value_counts())
  
  # most_common_index(df)
  