diff --git a/openAPI/dummy_data_maker.py b/openAPI/dummy_data_maker.py
index a914c3c..050df02 100644
--- a/openAPI/dummy_data_maker.py
+++ b/openAPI/dummy_data_maker.py
@@ -2,12 +2,14 @@
 import string
 from datetime import datetime
 
+
 def generate_dummy_email():
     domains = ["example.com", "test.com", "dummy.com"]
     username = ''.join(random.choices(string.ascii_lowercase + string.digits, k=7))
     domain = random.choice(domains)
     return f"{username}@{domain}"
 
+
 def preprocessing_book_index(book_index):
     dummy_book_indx = "<p>Dummy Book Index<br>1.example index<br>2.example index<br>3.example index</p>"
     if not book_index.strip():
@@ -15,22 +17,25 @@ def preprocessing_book_index(book_index):
 
     return book_index.replace("\r\n", "")
 
+
 def generate_book_discount():
     values = [0, 10, 20]
     weights = [5, 3, 2]  # 각 값에 대한 가중치, 50%, 30%, 20%의 비율
     return random.choices(values, weights=weights)[0]
 
+
 def generate_book_package():
     values = [0, 1]
     weights = [3, 7]  # 각 값에 대한 가중치, 30%, 70%의 비율
     return random.choices(values, weights=weights)[0]
 
-def preprocessing_book_published(date):
 
+def preprocessing_book_published(date):
     date_object = datetime.strptime(date, '%a, %d %b %Y %H:%M:%S %Z')
 
     return date_object.strftime('%Y-%m-%d')
 
+
 def generate_book_stock():
     values = [200, 300]
     weights = [5, 5]  # 각 값에 대한 가중치, 30%, 70%의 비율