try updating dtypes

README.md

@@ -21,27 +21,27 @@ dataset_info:
       - name: "NO."            
         dtype: int64            
       - name: "compound_name"   
-        dtype: object  
+        dtype: string  
       - name: "IUPAC_name"       
-        dtype: object 
+        dtype: string 
       - name: "SMILES"          
-        dtype: object            
+        dtype: string            
       - name: "CID"   
         dtype: float64  
       - name: "logBB"       
         dtype: float64 
       - name: "BBB+/BBB-"            
-        dtype: object            
+        dtype: string           
       - name: "Inchi"   
-        dtype: object 
+        dtype: string 
       - name: "threshold"       
         dtype: float64
       - name: "reference"       
-        dtype: object
+        dtype: string
       - name: "group"            
-        dtype: object            
+        dtype: string            
       - name: "comments" 
-        dtype: object 
+        dtype: string 
       - name: "ClusterNo"       
         dtype: int64
       - name: "MolCount"