125 lines
4.6 KiB
Python
125 lines
4.6 KiB
Python
"""PiggyBank implementation."""
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from __future__ import annotations
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from os.path import exists
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from typing import List
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from piggybank import PIGGYBANK_FILE_EXTENSION
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from piggybank.currencies import CURRENCIES, DEFAULT_CURRENCY, \
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CurrencyIsNotSupportedError, CurrenciesCoinCountMismatchError, \
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CurrencyMismatchError
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from piggybank.transaction import Transaction, TYPE_INCOME
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__all__ = ["PiggyBank"]
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class PiggyBank:
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"""This class stores array of transactions and perform some actions on it."""
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def __init__(self, currency: str = DEFAULT_CURRENCY) -> None:
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if currency.upper() in CURRENCIES:
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self._currency = currency.upper()
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else:
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raise CurrencyIsNotSupportedError
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self._transactions = []
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def transact(self, coins: List[int], direction: str = TYPE_INCOME) -> None:
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"""Make a transaction."""
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if len(coins) != CURRENCIES[self.currency]["count"]:
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raise ValueError("Length of passed coins list doesn't match the "
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f"currency's coins count. ({len(coins)} "
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f"!= {CURRENCIES[self.currency]['count']})")
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self._transactions.append(Transaction(coins, direction))
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for coin_count in self.count:
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if coin_count < 0:
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del self._transactions[-1]
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raise ValueError(
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"You can't take out more than you have.")
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@property
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def count(self) -> List[int]:
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"""Returns a list of counts for each face value in total."""
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count = [0] * CURRENCIES[self.currency]["count"]
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for tr in self.transactions:
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count = [x + y if tr.direction == TYPE_INCOME
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else x - y for x, y in zip(count, tr.coins)]
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return count
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@property
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def sum(self) -> List[int]:
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"""Returns a list of sums for each face value multiplied by its
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currency's multipilers."""
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return [x * y for x, y
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in zip(self.count, CURRENCIES[self.currency]["multipliers"])]
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@property
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def total(self) -> int:
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"""Returns a total amount of money stored in a PiggyBank."""
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return sum(self.sum)
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@staticmethod
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def from_file(filename: str) -> PiggyBank:
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"""Returns a PiggyBank object loaded from a file with name
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`filename`."""
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piggybank = PiggyBank()
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piggybank.load(filename)
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return piggybank
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def save(self, filename: str) -> None:
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"""Writes a PiggyBank object to a file with name `filename`."""
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if not filename.endswith(PIGGYBANK_FILE_EXTENSION):
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filename += PIGGYBANK_FILE_EXTENSION
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with open(filename, 'w') as _file:
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_file.write(f"{self.currency}\n")
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for transaction in self.transactions:
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_file.write(f"{str(transaction)}\n")
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def load(self, filename: str) -> None:
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"""Loads a PiggyBank from a file with name `filename`."""
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if not filename.endswith(PIGGYBANK_FILE_EXTENSION):
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filename += PIGGYBANK_FILE_EXTENSION
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if not exists(filename):
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raise FileNotFoundError(filename)
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with open(filename, 'r') as _file:
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currency = _file.readline()[:-1]
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if currency not in CURRENCIES:
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raise CurrencyIsNotSupportedError
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else:
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self.currency = currency
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for transaction in _file:
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self._transactions.append(Transaction.from_string(transaction))
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@property
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def currency(self) -> str:
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"""Returns a currency of a PiggyBank."""
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return self._currency
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@currency.setter
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def currency(self, currency: str) -> None:
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"""Sets a currency of a PiggyBank with check for support. And if count
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of coins doesn't match the old currency it won't set a new one."""
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currency = currency.upper()
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if currency not in CURRENCIES:
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raise CurrencyIsNotSupportedError
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if CURRENCIES[currency]["count"] != CURRENCIES[self.currency]["count"]:
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raise CurrenciesCoinCountMismatchError
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self._currency = currency
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@property
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def transactions(self) -> List[Transaction]:
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"""Returns a list of transactions."""
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return self._transactions
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def __eq__(self, piggybank: PiggyBank) -> str:
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"""It compares only currency."""
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return self.currency == piggybank._currency
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def __add__(self, piggybank: PiggyBank) -> PiggyBank:
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if self != piggybank:
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raise CurrencyMismatchError
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new = PiggyBank(self.currency)
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new._transactions = self.transactions + piggybank._transactions
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return new
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