Minor refactoring of Transaction class.

piggybank/transaction.py

@@ -2,9 +2,9 @@
 
 from __future__ import annotations
 from time import strftime, strptime, gmtime
-from typing import Optional
+from typing import Optional, List
 
-__all__ = ["Transaction", "TYPE_INCOME", "TYPE_OUTCOME"]
+__all__ = ["Transaction", "TYPE_INCOME", "TYPE_OUTCOME", "TIME_FORMAT"]
 
 TYPE_INCOME = "in"
 TYPE_OUTCOME = "out"
@@ -12,10 +12,14 @@ TIME_FORMAT = "%Y-%m-%dT%H:%M:%S"
 
 
 class Transaction:
-    """Transaction consists of a timestamp, a direction
-    and an array of coins. It doesn't depend on a currency. Only coins count is
-    stored."""
-    def __init__(self, coins, direction: str = TYPE_INCOME,
+    """An object that holds a transaction.
+    
+    Arguments:
+        - coins -- a list of numbers represent count for each face value;
+        - direction -- is this income or outcome. Takes TYPE_INCOME
+                       or TYPE_OUTCOME;
+        - timestamp -- date and time formated accordingly to TIME_FORMAT."""
+    def __init__(self, coins: List[int], direction: str = TYPE_INCOME,
                  timestamp: Optional[str] = None) -> None:
         self.coins = coins
         if direction in [TYPE_INCOME, TYPE_OUTCOME]:
@@ -38,7 +42,7 @@ class Transaction:
         """Makes a Transaction object from its string output."""
         timestamp, direction, coins = transaction.split()
 
-        coins = [int(coin) for coin in coins.split(",")]
+        coins = list(map(int, coins.split(",")))
         return Transaction(coins, direction, timestamp)
 
     def __str__(self) -> str: