diff --git a/cdqa/utils/converter.py b/cdqa/utils/converter.py
index 9e78b82..888ac20 100644
--- a/cdqa/utils/converter.py
+++ b/cdqa/utils/converter.py
@@ -3,61 +3,62 @@
 from tqdm import tqdm
 import uuid
 
+
 def df2squad(df, squad_version='v2.0', output_dir=None, filename=None):
-   """
-    Converts a pandas dataframe with columns ['title', 'content'] to a json file with SQuAD format.
+    """
+     Converts a pandas dataframe with columns ['title', 'content'] to a json file with SQuAD format.
 
-    Parameters
-   ----------
-    df : pandas.DataFrame
-        a pandas dataframe with columns ['title', 'content']
-    squad_version : str, optional
-        the SQuAD dataset version format (the default is 'v2.0')
-    output_dir : str, optional
-        Enable export of output (the default is None)
-    filename : str, optional
-        [description]
+     Parameters
+    ----------
+     df : pandas.DataFrame
+         a pandas dataframe with columns ['title', 'content']
+     squad_version : str, optional
+         the SQuAD dataset version format (the default is 'v2.0')
+     output_dir : str, optional
+         Enable export of output (the default is None)
+     filename : str, optional
+         [description]
 
-   Returns
-   -------
-   json_data: dict
-       A json object with SQuAD format
+    Returns
+    -------
+    json_data: dict
+        A json object with SQuAD format
 
-    Examples
-    --------
-    >>> from ast import literal_eval
-    >>> import pandas as pd
-    >>> from cdqa.utils.converter import df2squad, filter_paragraphs
+     Examples
+     --------
+     >>> from ast import literal_eval
+     >>> import pandas as pd
+     >>> from cdqa.utils.converter import df2squad, filter_paragraphs
 
-    >>> df = pd.read_csv('../data/bnpp_newsroom_v1.0/bnpp_newsroom-v1.0.csv', converters={'paragraphs': literal_eval})
-    >>> df['paragraphs'] = df['paragraphs'].apply(filter_paragraphs)
+     >>> df = pd.read_csv('../data/bnpp_newsroom_v1.0/bnpp_newsroom-v1.0.csv', converters={'paragraphs': literal_eval})
+     >>> df['paragraphs'] = df['paragraphs'].apply(filter_paragraphs)
 
-    >>> json_data = df2squad(df=df, squad_version='v2.0', output_dir='../data', filename='bnpp_newsroom-v1.0')
-   """
+     >>> json_data = df2squad(df=df, squad_version='v2.0', output_dir='../data', filename='bnpp_newsroom-v1.0')
+    """
 
+    json_data = {}
+    json_data['version'] = squad_version
+    json_data['data'] = []
 
-   json_data = {}
-   json_data['version'] = squad_version
-   json_data['data'] = []
+    for index, row in tqdm(df.iterrows()):
+        temp = {'title': row['title'],
+                'paragraphs': []}
+        for paragraph in row['paragraphs']:
+            temp['paragraphs'].append({'context': paragraph,
+                                       'qas': []})
+        json_data['data'].append(temp)
 
-   for index, row in tqdm(df.iterrows()):
-       temp = {'title': row['title'],
-               'paragraphs': []}
-       for paragraph in row['paragraphs']:
-           temp['paragraphs'].append({'context': paragraph,
-                                      'qas': []})
-       json_data['data'].append(temp)
+    if output_dir:
+        with open(os.path.join(output_dir, '{}.json'.format(filename)), 'w') as outfile:
+            json.dump(json_data, outfile)
 
-   if output_dir:
-       with open(os.path.join(output_dir, '{}.json'.format(filename)), 'w') as outfile:
-           json.dump(json_data, outfile)
+    return json_data
 
-   return json_data
 
 def generate_squad_examples(question, closest_docs_indices, metadata):
     """
     Creates a SQuAD examples json object for a given for a given question using outputs of retriever and document database.
-    
+
     Parameters
     ----------
     question : [type]
@@ -66,7 +67,7 @@ def generate_squad_examples(question, closest_docs_indices, metadata):
         [description]
     metadata : [type]
         [description]
-    
+
     Returns
     -------
     squad_examples: list
@@ -81,35 +82,35 @@ def generate_squad_examples(question, closest_docs_indices, metadata):
 
     """
 
-    
     squad_examples = []
-    
+
     metadata_sliced = metadata.loc[closest_docs_indices]
-    
+
     for index, row in tqdm(metadata_sliced.iterrows()):
         temp = {'title': row['title'],
-               'paragraphs': []}
-        
+                'paragraphs': []}
+
         for paragraph in row['paragraphs']:
             temp['paragraphs'].append({'context': paragraph,
                                        'qas': [{'answers': [],
                                                 'question': question,
                                                 'id': str(uuid.uuid1())}]
-                                      })
+                                       })
 
-            squad_examples.append(temp)
+        squad_examples.append(temp)
 
     return squad_examples
 
-def filter_paragraphs(paragraphs):
+
+def filter_paragraphs(paragraphs, min_length=10, max_length=250):
     """
     Filters out paragraphs shorter than X words and longer than Y words
-    
+
     Parameters
     ----------
     paragraphs : [type]
         [description]
-    
+
     Returns
     -------
     [type]
@@ -126,5 +127,6 @@ def filter_paragraphs(paragraphs):
 
     """
 
-    paragraphs_filtered = [paragraph for paragraph in paragraphs if len(paragraph.split()) >= 10 and len(paragraph.split()) <= 250]
+    paragraphs_filtered = [paragraph for paragraph in paragraphs if len(
+        paragraph.split()) >= min_length and len(paragraph.split()) <= max_length]
     return paragraphs_filtered