Update get_paper.py

get_paper.py

@@ -2,14 +2,15 @@ import arxiv
 
 
 def get_paper(paper=""):
-    id = paper.split(" - ")
-    print("id= ", id)
-
-    paper = next(arxiv.Search(id_list=[id[-1]]).results())
-    print("paper title= ", paper.title)
-    name = str(paper.title) + '.pdf'
-    name = name.replace('?', '')
-    name = "downloads/" + name
-    paper.download_pdf(filename=name)
+    if paper:
+        id = paper.split(" - ")
+        print("id= ", id)
+    
+        paper = next(arxiv.Search(id_list=[id[-1]]).results())
+        print("paper title= ", paper.title)
+        name = str(paper.title) + '.pdf'
+        name = name.replace('?', '')
+        name = "downloads/" + name
+        paper.download_pdf(filename=name)
 
     return(paper)