Update main.py

main.py

@@ -32,28 +32,32 @@ def read_root():
     return HTMLResponse(content=html_content)
 
 @app.get("/title2ref/")
-async def title2doi(title:str):
+async def title2doi(title: str):
     cr = Crossref()
 
-    result = cr.works(query = title)
-    for i, item in enumerate(result['message']['items']):
-        if item['title'][0] == title:
-            doi = result['message']['items'][i]['DOI']
-            break
+    result = cr.works(query=title)
     
-    url = BASE_URL + doi
-    req = urllib.request.Request(url)
-    req.add_header('Accept', 'application/x-bibtex')
+    # Check if the result has items and the title matches
+    if result['message']['items']:
+        for item in result['message']['items']:
+            if 'title' in item and item['title'][0] == title:
+                doi = item['DOI']
+                url = BASE_URL + doi
+                req = urllib.request.Request(url)
+                req.add_header('Accept', 'application/x-bibtex')
 
-    try:
-        with urllib.request.urlopen(req) as f:
-            bibtex = f.read().decode()
-        return {"bibtex": bibtex}
-    except HTTPError as e:
-        if e.code == 404:
-            raise HTTPException(status_code=404, detail="DOI not found")
-        else:
-            raise HTTPException(status_code=503, detail="Service unavailable")
+                try:
+                    with urllib.request.urlopen(req) as f:
+                        bibtex = f.read().decode()
+                    return {"bibtex": bibtex}
+                except HTTPError as e:
+                    if e.code == 404:
+                        raise HTTPException(status_code=404, detail="DOI not found")
+                    else:
+                        raise HTTPException(status_code=503, detail="Service unavailable")
+
+    # If no matching title found
+    raise HTTPException(status_code=404, detail="Title not found, please enter DOI")
             
 @app.get("/doi2ref/")
 async def doi2ref(doi: str):