diff --git a/3/rucksack.py b/3/rucksack.py
index 2eb6a33..838dd31 100644
--- a/3/rucksack.py
+++ b/3/rucksack.py
@@ -3,47 +3,48 @@ import string
 from aocd.models import Puzzle
 from aocd import submit
 
+
 def eval_item_priority(rucksack: str) -> int:
-    '''
-        evaluates the priority of a common item
-    '''
+    """
+    evaluates the priority of a common item
+    """
 
     # create a map of priority values
-    priorities = dict(zip(string.ascii_letters, range(1,53)))
+    priorities = dict(zip(string.ascii_letters, range(1, 53)))
 
     # slize rucksack into compartments
     size = len(rucksack)
-    a,b = rucksack[:size//2], rucksack[size//2:]
+    a, b = rucksack[: size // 2], rucksack[size // 2 :]
 
     # find the common item
-    common = ''.join(
-        set(a).intersection(b)
-    )
+    common = "".join(set(a).intersection(b))
 
     # return the priority
     return priorities[common]
 
+
 def eval_badge_priority(rucksacks: list) -> int:
-    '''
-        evaluate the priority of duplicate items over groups of three rucksacks
-    '''
+    """
+    evaluate the priority of duplicate items over groups of three rucksacks
+    """
 
     # create a map of priority values
-    priorities = dict(zip(string.ascii_letters, range(1,53)))
+    priorities = dict(zip(string.ascii_letters, range(1, 53)))
 
-    # find common item among three sets
-    common = ''.join(
-        set(rucksacks[0]) & set(rucksacks[1]) & set(rucksacks[2])
-    )
+    # find common item amongst three sets
+    common = "".join(set(rucksacks[0]) & set(rucksacks[1]) & set(rucksacks[2]))
 
+    # convert to priority list
     return priorities[common]
 
+
 def parse_input(data: list) -> list:
-    '''
-        parses the input data and generates a list
-    '''
+    """
+    parses the input data and generates a list
+    """
     # split move set into a list of rounds
-    return [ move for move in data.split('\n')]
+    return [move for move in data.split("\n")]
+
 
 if __name__ == "__main__":
     # get puzzle and parse data
@@ -52,12 +53,13 @@ if __name__ == "__main__":
 
     # part a: determine the priority of dupplicate items in compartments
     answer_a = sum([eval_item_priority(rucksack) for rucksack in supplies])
-    print(f'sum of priorities of all common items amongst compartments: {answer_a}')
-    submit(answer_a, part='a', day=3, year=2022)
+    print(f"sum of priorities of all common items amongst compartments: {answer_a}")
+    submit(answer_a, part="a", day=3, year=2022)
 
     # part b: determine the priority of common items in groups of three
     # split the supply list into groups of three
-    rucksacks = [ supplies[i:i+3] for i in range(0,len(supplies),3) ]
-    answer_b = sum([ eval_badge_priority(rucksack) for rucksack in rucksacks ])
-    print(f'sum of priorities of all common items amongst groups of three: {answer_b}')
-    submit(answer_b, part='b', day=3, year=2022)
+    groups = [supplies[i : i + 3] for i in range(0, len(supplies), 3)]
+    # create a list of each groups priority and sum it all up
+    answer_b = sum([eval_badge_priority(group) for group in groups])
+    print(f"sum of priorities of all common items amongst groups of three: {answer_b}")
+    submit(answer_b, part="b", day=3, year=2022)