code: def get_dupes(
      df: pd.DataFrame,
      column_names: Optional[
          Union[str, Iterable[str], Hashable]
      ] = None,
  ) -> pd.DataFrame:
      """
      Return all duplicate rows.
  
      This method does not mutate the original DataFrame.
  
      Examples:
          Method chaining syntax:
  
          >>> import pandas as pd
          >>> import janitor
          >>> df = pd.DataFrame({
          ...     "item": ["shoe", "shoe", "bag", "shoe", "bag"],
          ...     "quantity": [100, 100, 75, 200, 75],
          ... })
          >>> df
             item  quantity
          0  shoe       100
          1  shoe       100
          2   bag        75
          3  shoe       200
          4   bag        75
          >>> df.get_dupes()
             item  quantity
          0  shoe       100
          1  shoe       100
          2   bag        75
          4   bag        75
  
          Optional `column_names` usage:
  
          >>> import pandas as pd
          >>> import janitor
          >>> df = pd.DataFrame({
          ...     "item": ["shoe", "shoe", "bag", "shoe", "bag"],
          ...     "quantity": [100, 100, 75, 200, 75],
          ... })
          >>> df
             item  quantity
          0  shoe       100
          1  shoe       100
          2   bag        75
          3  shoe       200
          4   bag        75
          >>> df.get_dupes(column_names=["item"])
             item  quantity
          0  shoe       100
          1  shoe       100
          2   bag        75
          3  shoe       200
          4   bag        75
          >>> df.get_dupes(column_names=["quantity"])
             item  quantity
          0  shoe       100
          1  shoe       100
          2   bag        75
          4   bag        75
  
      Args:
          df: The pandas DataFrame object.
          column_names: A column name or an iterable
              (list or tuple) of column names. Following pandas API, this only
              considers certain columns for identifying duplicates. Defaults
              to using all columns.
  
      Returns:
          The duplicate rows, as a pandas DataFrame.
      """
      return df.loc[df.duplicated(subset=column_names, keep=False)]
  
imports: from typing import Hashable, Iterable, Optional, Union
  import pandas
  import pandas_flavor
  from janitor.utils import deprecated_alias
label_desc: Use image node_id 1 for calling a global function with example usage: get_dupes(df, column_names) and returns: df