Also support multiple tickers for mapping

Example: COMP -> [COMP, COMP-USD]

README.md

@@ -22,7 +22,7 @@ It does not however validate or use a whitelist of tickers.
 * The results are in the order they are first found.
 * By default, the results are deduplicated, although this can be disabled.
 * A configurable blacklist of common false-positives is used.
-* A configurable remapping of specific tickers is supported.
+* A configurable remapping of tickers is supported.
 * For lower level use, a configurably created compiled regular expression can be accessed.
 
 ## Links
@@ -76,4 +76,7 @@ Python ≥3.8 is required. To install, run:
 >>> reticker.config.MAPPING["BTC"] = "BTC-USD"
 >>> reticker.TickerExtractor().extract("What is the Yahoo Finance symbol for BTC?")
 ['BTC-USD']
+>>> reticker.config.MAPPING["COMP"] = ["COMP", "COMP-USD"]
+>>> reticker.TickerExtractor().extract('Is COMP for the equity named "Compass" or for the crypto named "Compound"? I want both!')
+['COMP', 'COMP-USD']
 ```

reticker/config/__init__.py

@@ -1,8 +1,8 @@
 """Package config."""
 from pathlib import Path
-from typing import Dict, Final, List, Set
+from typing import Dict, Final, List, Set, Union
 
 _CONFIG_PATH: Final[Path] = Path(__file__).parent
 BLACKLIST_PATHS: Final[List[Path]] = list((_CONFIG_PATH / "blacklist").glob("*.txt"))
 BLACKLIST: Final[Set[str]] = set(term for path in BLACKLIST_PATHS for term in path.read_text().strip().split("\n"))
-MAPPING: Final[Dict[str, str]] = {}
+MAPPING: Final[Dict[str, Union[str, List[str]]]] = {}

reticker/reticker.py

@@ -87,8 +87,9 @@ def append_patterns(part1: str, part2: str) -> None:
     def extract(self, text: str) -> List[str]:
         """Return possible tickers extracted from the given text."""
         matches = [match.upper() for match in self.pattern.findall(text)]
-        matches = [match for match in matches if match not in config.BLACKLIST]  # Is done _before_ 'mapping'.
+        matches = [match for match in matches if match not in config.BLACKLIST]  # Is done _before_ mapping.
         matches = [config.MAPPING.get(match, match) for match in matches]
+        matches = [inner_m for m_list in [[outer_m] if isinstance(outer_m, str) else outer_m for outer_m in matches] for inner_m in m_list]  # Conditional flattening of mapping.
         if self.deduplicate:
-            matches = list(dict.fromkeys(matches))  # Is done _after_ 'mapping'.
+            matches = list(dict.fromkeys(matches))  # Is done _after_ mapping.
         return matches

tests/test_extractor.py

@@ -52,7 +52,8 @@ def test_blacklist(self):
         reticker.config.BLACKLIST.remove("BLCN")
         self.assertEqual(reticker.config.BLACKLIST, original_blacklist)
 
-    def test_mapping(self):
+    def test_mapping_to_str(self):
+        self.assertNotIn("ADA", reticker.config.MAPPING)
         self.assertNotIn("BTC", reticker.config.MAPPING)
         text = "ADA BTC RIOT"
         self.assertEqual(self.default_ticker_extractor.extract(text), ["ADA", "BTC", "RIOT"])
@@ -69,6 +70,22 @@ def test_mapping(self):
         del reticker.config.MAPPING["BTC"]
         self.assertEqual(reticker.config.MAPPING, original_mapping)
 
+    def test_mapping_to_list(self):
+        self.assertNotIn("COMP", reticker.config.MAPPING)
+        self.assertNotIn("USD", reticker.config.MAPPING)
+        text = 'Is COMP for the equity "Compass, Inc." or is it for the cryptocurrency "Compound USD"?'
+        self.assertEqual(self.default_ticker_extractor.extract(text), ["COMP", "USD"])
+
+        original_mapping = reticker.config.MAPPING.copy()
+        reticker.config.MAPPING["COMP"] = ["COMP", "COMP-USD"]
+        self.assertEqual(self.default_ticker_extractor.extract(text), ["COMP", "COMP-USD", "USD"])
+        reticker.config.MAPPING["USD"] = ["DXY"]
+        self.assertEqual(self.default_ticker_extractor.extract(text), ["COMP", "COMP-USD", "DXY"])
+
+        del reticker.config.MAPPING["COMP"]
+        del reticker.config.MAPPING["USD"]
+        self.assertEqual(reticker.config.MAPPING, original_mapping)
+
 
 class TestCustomExtraction(unittest.TestCase):
     def test_prefixed_uppercase(self):