move function

xexe/rate_fetching.py

@@ -7,6 +7,7 @@ from money.currency import Currency, CurrencyHelper
 from money.money import Money
 from xecd_rates_client import XecdClient
 
+from xexe.constants import RATES_SOURCES
 from xexe.exchange_rates import ExchangeRate
 
 
@@ -79,3 +80,7 @@ class XERateFetcher(RateFetcher):
             rate_date=rate_date,
             rate=rate,
         )
+
+
+def build_rate_fetcher(rates_source: str):
+    return RATES_SOURCES[rates_source]()