Update README.md

README.md

@@ -21,10 +21,14 @@ task_ids: []
 ---
 
 ### dataset description
-We downloaded PubChem-10m dataset from [here](https://deepchemdata.s3-us-west-1.amazonaws.com/datasets/pubchem_10m.txt.zip) and canonicalized it using RDKit. And we removed some SMILES that cannot be read by RDKit.
-We used the following function to canonicalize the data.
-
+We downloaded PubChem-10m dataset from [here](https://deepchemdata.s3-us-west-1.amazonaws.com/datasets/pubchem_10m.txt.zip) and canonicalized it.
+We used the following function to canonicalize the data and removed some SMILES that cannot be read by RDKit.
+    
+```python:
 from rdkit import Chem
 def canonicalize(mol):
     mol = Chem.MolToSmiles(Chem.MolFromSmiles(mol),True)
-    return mol
+    return mol 
+```
+
+We randomly split the preprocessed data into train and validation. The ratio is 9 : 1.