code: def currency_df():
      df = pd.DataFrame(
          {
              "a_col": [" 24.56", "-", "(12.12)", "1,000,000"],
              "d_col": ["", "foo", "1.23 dollars", "-1,000 yen"],
          }
      )
      return df
  
file_path: pyjanitor/tests/functions/test_currency_column_to_numeric.py
imports: import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
  from janitor.functions.currency_column_to_numeric import _currency_column_to_numeric
label_desc: Use image node_id 1 for calling a global function with example usage: currency_df() and returns: df