diff --git a/class_person.py b/class_person.py
index c0eae75..be80e97 100755
--- a/class_person.py
+++ b/class_person.py
@@ -8,6 +8,7 @@ class Person():
     def __repr__(self):
         return repr((self.name, self.age))
 
+
 people = [
     Person("tom", 22),
     Person("jack", 11),
diff --git a/functions.py b/functions.py
index bd91ffe..5f40280 100644
--- a/functions.py
+++ b/functions.py
@@ -2,21 +2,25 @@
 
 do_add = lambda a, b: a + b
 
+
 def do_add_2(a, b):
     return a + b
 
-def incr(base, inc = 1):
+
+def incr(base, inc=1):
     return base + inc
 
-def var_args(first_arg = "first", *args):
+
+def var_args(first_arg="first", *args):
     print("fist arg:", first_arg)
     print("rest args:", args)
 
+
 if __name__ == "__main__":
     print("1 + 2 =", do_add(1, 2))
     print("1 + 2 =", do_add_2(1, 2))
     print("1 inc 1 =", incr(1))
-    print("1 inc 1 =", incr(1, inc = 1))
-    print("1 inc 2 =", incr(1, inc = 2))
+    print("1 inc 1 =", incr(1, inc=1))
+    print("1 inc 2 =", incr(1, inc=2))
     var_args()
     var_args("fist argument", "1", "2", "3")
diff --git a/leap_year.py b/leap_year.py
index fa50033..6a1002b 100644
--- a/leap_year.py
+++ b/leap_year.py
@@ -3,6 +3,7 @@
 def is_leap_year(year: int):
     return year % 4 == 0 and year % 100 != 0 or year % 400 == 0
 
+
 if __name__ == "__main__":
     print(1582, is_leap_year(1582))
     print(2000, is_leap_year(2000))
diff --git a/tls_certificate.py b/tls_certificate.py
index 0c0e692..b8eaf47 100755
--- a/tls_certificate.py
+++ b/tls_certificate.py
@@ -2,6 +2,7 @@
 import socket
 import ssl
 
+
 def get_server_certificate(hostname, port=443):
     # context = ssl.create_default_context()
     context = ssl._create_unverified_context()
@@ -11,9 +12,10 @@ def get_server_certificate(hostname, port=443):
             cert = ssock.getpeercert()
             return cert
 
+
 # not success, but why?
 if __name__ == "__main__":
     certificate = get_server_certificate("hatter.ink")
     print(f"Certificate: {certificate}")
     for key, value in certificate.items():
-        print(f"{key}: {value}")
\ No newline at end of file
+        print(f"{key}: {value}")