text: import pandas as pd
  from locale import atof
  
  usdToEurDf = pd.read_csv("BBEX3.D.USD.EUR.BB.AC.000.csv", sep=';', names=['date', 'value','comments'])
  
  def findValidRowByDate(date):
      while True:
          rows = usdToEurDf.loc[usdToEurDf['date'] == date]
          if len(rows.index) == 1:
              return rows.iloc[0]
  
  def usdToEur(date, valueInUSD):
      value = usdToEurDf.loc[usdToEurDf['date'] == date].iloc[0]['value']
      value = atof(value)
      return valueInUSD / value
  
  def eurToUsd(date, valueInEUR):
      row = findValidRowByDate(date)
      value = row['value']
      value = atof(value)
      return valueInEUR * value
  