Create evidence.py

evidence.py

@@ -0,0 +1,27 @@
+# evidence.py
+import re
+from collections import defaultdict
+
+# seed hints – extend over time
+BUCKET_HINTS = {
+    "2019–2022": ["covid", "covid-19", "sars-cov-2", "lockdown", "n95", "zoom", "pfizer", "pcr", "remote school"],
+    "2023–present": ["chatgpt", "gpt-4", "llm", "generative ai", "tiktok", "threads", "hybrid work"],
+    "1991–2008": ["myspace", "y2k", "dial-up", "iraq war", "windows xp"],
+    "1946–1990": ["cold war", "sputnik", "berlin wall", "vietnam", "ussr"],
+    "1900–1945": ["world war i", "world war ii", "blitz", "rationing", "great depression"],
+    "2009–2015": ["iphone 4", "ipad", "app store", "snapchat", "vine"],
+    "2016–2018": ["fidget spinner", "fortnite", "instagram stories"],
+    "pre-1900": ["telegraph", "steam locomotive", "victorian"],
+}
+
+YEAR_RE = re.compile(r"\b(1[89]\d{2}|20\d{2})\b")
+
+def extract_evidence(text: str):
+    t = text.lower()
+    years = YEAR_RE.findall(t)
+    hits = defaultdict(list)
+    for bucket, terms in BUCKET_HINTS.items():
+        for term in terms:
+            if term in t:
+                hits[bucket].append(term)
+    return {"years": years, "keyword_hits": dict(hits)}