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PiggyBank/piggybank/transaction.py

51 lines
1.8 KiB
Python

"""Transaction class implementation."""
from __future__ import annotations
from time import strftime, strptime, gmtime
from typing import Optional
__all__ = ["Transaction", "TYPE_INCOME", "TYPE_OUTCOME"]
TYPE_INCOME = "in"
TYPE_OUTCOME = "out"
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,
timestamp: Optional[str] = None) -> None:
self.coins = coins
if direction in [TYPE_INCOME, TYPE_OUTCOME]:
self.direction = direction
else:
raise ValueError(f"Direction may only be"
f"'{TYPE_INCOME}' or '{TYPE_OUTCOME}'")
if timestamp is None:
self.timestamp = strftime(TIME_FORMAT, gmtime())
else:
try:
strptime(timestamp, TIME_FORMAT)
except ValueError:
raise ValueError(f"Timestamp {timestamp} has wrong format. "
f"The right one is '{TIME_FORMAT}''")
self.timestamp = timestamp
@staticmethod
def from_string(transaction: str) -> Transaction:
"""Makes a Transaction object from its string output."""
timestamp, direction, coins = transaction.split()
coins = [int(coin) for coin in coins.split(",")]
return Transaction(coins, direction, timestamp)
def __str__(self) -> str:
return f"{self.timestamp} {self.direction} " \
f"{','.join(str(c) for c in self.coins)}"
def __repr__(self) -> str:
return f"Transaction(coins={self.coins!r}," \
f"direction={self.direction!r}, timestamp={self.timestamp!r})"