mirror of
https://github.com/spiral-project/ihatemoney.git
synced 2025-04-28 17:32:38 +02:00
Merge 23d5b73ae1 into 56bee93346
This commit is contained in:
gr4viton
GitHub
commit
8b5df5d336
1 changed files with 85 additions and 188 deletions
|
|
@ -1,10 +1,17 @@
|
|||
import csv
|
||||
import traceback
|
||||
import warnings
|
||||
from abc import ABC, abstractmethod
|
||||
from decimal import Decimal
|
||||
from typing import Dict, Optional
|
||||
|
||||
from cachetools import TTLCache, cached
|
||||
import requests
|
||||
|
||||
|
||||
NO_CURRENCY = "XXX"
|
||||
ExchangeRates = Dict[str, float]
|
||||
|
||||
class Singleton(type):
|
||||
_instances = {}
|
||||
|
||||
|
|
@ -14,205 +21,93 @@ class Singleton(type):
|
|||
return cls._instances[cls]
|
||||
|
||||
|
||||
class CurrencyConverter(object, metaclass=Singleton):
|
||||
# Get exchange rates
|
||||
no_currency = "XXX"
|
||||
class ExchangeRateGetter(ABC):
|
||||
|
||||
def get_rates(self) -> Optional[ExchangeRates]:
|
||||
"""Method to retrieve a list of currency conversion rates.
|
||||
|
||||
Returns:
|
||||
currencies: dict - key is a three-letter currency, value is float of conversion to base currency
|
||||
"""
|
||||
try:
|
||||
return self._get_rates()
|
||||
except Exception:
|
||||
warnings.warn(
|
||||
f"Exchange rate getter failed - {traceback.format_exc(limit=0).strip()}"
|
||||
)
|
||||
|
||||
@abstractmethod
|
||||
def _get_rates(self) -> Optional[ExchangeRates]:
|
||||
"""Actual implementation of the exchange rate getter."""
|
||||
raise NotImplementedError
|
||||
|
||||
|
||||
class ApiExchangeRate(ExchangeRateGetter):
|
||||
api_url = "https://api.exchangerate.host/latest?base=USD"
|
||||
|
||||
def _get_rates(self) -> Optional[ExchangeRates]:
|
||||
return requests.get(self.api_url).json()["rates"] # TODO not working currently probably
|
||||
|
||||
|
||||
class UserExchangeRate(ExchangeRateGetter):
|
||||
user_csv_file = "path/to/file.csv"
|
||||
|
||||
def _get_rates(self) -> Optional[ExchangeRates]:
|
||||
"""Get rates from user defined csv.
|
||||
|
||||
The user_csv_file should contain the currency conversions to "USD" without 1 header row
|
||||
Example:
|
||||
```
|
||||
currency_code,fx_rate_to_USD
|
||||
CZK,25.0
|
||||
...
|
||||
```
|
||||
|
||||
TODO: make it work bi-directionally
|
||||
TODO: document for the user where to place the file
|
||||
"""
|
||||
reader = csv.reader(self.user_csv_file)
|
||||
|
||||
rates = {}
|
||||
for row in reader:
|
||||
from_currency = row[0]
|
||||
rate = float(row[1])
|
||||
# TODO add validation and exception handling for typos
|
||||
rates[from_currency] = rate
|
||||
return rates
|
||||
|
||||
|
||||
class HardCodedExchangeRate(ExchangeRateGetter):
|
||||
|
||||
def _get_rates(self) -> Optional[dict]:
|
||||
return {"USD": 1.0} # TODO fill in more
|
||||
|
||||
|
||||
class CurrencyConverter(object, metaclass=Singleton):
|
||||
no_currency = NO_CURRENCY
|
||||
|
||||
def __init__(self):
|
||||
pass
|
||||
|
||||
@cached(cache=TTLCache(maxsize=1, ttl=86400))
|
||||
def get_rates(self):
|
||||
try:
|
||||
rates = requests.get(self.api_url).json()["rates"]
|
||||
except Exception:
|
||||
warnings.warn(
|
||||
f"Call to {self.api_url} failed: {traceback.format_exc(limit=0).strip()}"
|
||||
)
|
||||
# In case of any exception, let's have an empty value
|
||||
"""Try to retrieve the exchange rate from various sources, defaulting to hard coded values."""
|
||||
for provider in [ApiExchangeRate, UserExchangeRate, HardCodedExchangeRate]:
|
||||
if rates:= provider.get_rates():
|
||||
break
|
||||
else:
|
||||
rates = {}
|
||||
rates[self.no_currency] = 1.0
|
||||
rates[NO_CURRENCY] = 1.0
|
||||
return rates
|
||||
|
||||
def get_currencies(self, with_no_currency=True):
|
||||
currencies = [
|
||||
"AED",
|
||||
"AFN",
|
||||
"ALL",
|
||||
"AMD",
|
||||
"ANG",
|
||||
"AOA",
|
||||
"ARS",
|
||||
"AUD",
|
||||
"AWG",
|
||||
"AZN",
|
||||
"BAM",
|
||||
"BBD",
|
||||
"BDT",
|
||||
"BGN",
|
||||
"BHD",
|
||||
"BIF",
|
||||
"BMD",
|
||||
"BND",
|
||||
"BOB",
|
||||
"BRL",
|
||||
"BSD",
|
||||
"BTC",
|
||||
"BTN",
|
||||
"BWP",
|
||||
"BYN",
|
||||
"BZD",
|
||||
"CAD",
|
||||
"CDF",
|
||||
"CHF",
|
||||
"CLF",
|
||||
"CLP",
|
||||
"CNH",
|
||||
"CNY",
|
||||
"COP",
|
||||
"CRC",
|
||||
"CUC",
|
||||
"CUP",
|
||||
"CVE",
|
||||
"CZK",
|
||||
"DJF",
|
||||
"DKK",
|
||||
"DOP",
|
||||
"DZD",
|
||||
"EGP",
|
||||
"ERN",
|
||||
"ETB",
|
||||
"EUR",
|
||||
"FJD",
|
||||
"FKP",
|
||||
"GBP",
|
||||
"GEL",
|
||||
"GGP",
|
||||
"GHS",
|
||||
"GIP",
|
||||
"GMD",
|
||||
"GNF",
|
||||
"GTQ",
|
||||
"GYD",
|
||||
"HKD",
|
||||
"HNL",
|
||||
"HRK",
|
||||
"HTG",
|
||||
"HUF",
|
||||
"IDR",
|
||||
"ILS",
|
||||
"IMP",
|
||||
"INR",
|
||||
"IQD",
|
||||
"IRR",
|
||||
"ISK",
|
||||
"JEP",
|
||||
"JMD",
|
||||
"JOD",
|
||||
"JPY",
|
||||
"KES",
|
||||
"KGS",
|
||||
"KHR",
|
||||
"KMF",
|
||||
"KPW",
|
||||
"KRW",
|
||||
"KWD",
|
||||
"KYD",
|
||||
"KZT",
|
||||
"LAK",
|
||||
"LBP",
|
||||
"LKR",
|
||||
"LRD",
|
||||
"LSL",
|
||||
"LYD",
|
||||
"MAD",
|
||||
"MDL",
|
||||
"MGA",
|
||||
"MKD",
|
||||
"MMK",
|
||||
"MNT",
|
||||
"MOP",
|
||||
"MRU",
|
||||
"MUR",
|
||||
"MVR",
|
||||
"MWK",
|
||||
"MXN",
|
||||
"MYR",
|
||||
"MZN",
|
||||
"NAD",
|
||||
"NGN",
|
||||
"NIO",
|
||||
"NOK",
|
||||
"NPR",
|
||||
"NZD",
|
||||
"OMR",
|
||||
"PAB",
|
||||
"PEN",
|
||||
"PGK",
|
||||
"PHP",
|
||||
"PKR",
|
||||
"PLN",
|
||||
"PYG",
|
||||
"QAR",
|
||||
"RON",
|
||||
"RSD",
|
||||
"RUB",
|
||||
"RWF",
|
||||
"SAR",
|
||||
"SBD",
|
||||
"SCR",
|
||||
"SDG",
|
||||
"SEK",
|
||||
"SGD",
|
||||
"SHP",
|
||||
"SLL",
|
||||
"SOS",
|
||||
"SRD",
|
||||
"SSP",
|
||||
"STD",
|
||||
"STN",
|
||||
"SVC",
|
||||
"SYP",
|
||||
"SZL",
|
||||
"THB",
|
||||
"TJS",
|
||||
"TMT",
|
||||
"TND",
|
||||
"TOP",
|
||||
"TRY",
|
||||
"TTD",
|
||||
"TWD",
|
||||
"TZS",
|
||||
"UAH",
|
||||
"UGX",
|
||||
"USD",
|
||||
"UYU",
|
||||
"UZS",
|
||||
"VEF",
|
||||
"VES",
|
||||
"VND",
|
||||
"VUV",
|
||||
"WST",
|
||||
"XAF",
|
||||
"XAG",
|
||||
"XAU",
|
||||
"XCD",
|
||||
"XDR",
|
||||
"XOF",
|
||||
"XPD",
|
||||
"XPF",
|
||||
"XPT",
|
||||
"YER",
|
||||
"ZAR",
|
||||
"ZMW",
|
||||
"ZWL",
|
||||
]
|
||||
def get_currencies(self, with_no_currency: bool=True) -> list:
|
||||
currencies = list(self.get_rates.keys())
|
||||
if with_no_currency:
|
||||
currencies.append(self.no_currency)
|
||||
return currencies
|
||||
|
||||
def exchange_currency(self, amount, source_currency, dest_currency):
|
||||
def exchange_currency(self, amount: float, source_currency: str, dest_currency: str) -> float:
|
||||
"""Return the money amount converted from source_currency to dest_currency."""
|
||||
if (
|
||||
source_currency == dest_currency
|
||||
or source_currency == self.no_currency
|
||||
|
|
@ -223,6 +118,8 @@ class CurrencyConverter(object, metaclass=Singleton):
|
|||
rates = self.get_rates()
|
||||
source_rate = rates[source_currency]
|
||||
dest_rate = rates[dest_currency]
|
||||
new_amount = (float(amount) / source_rate) * dest_rate
|
||||
# round to two digits because we are dealing with money
|
||||
return round(new_amount, 2)
|
||||
# Using Decimal to not introduce floating-point operation absolute errors
|
||||
new_amount = (Decimal(amount) / Decimal(source_rate)) * Decimal(dest_rate)
|
||||
# dealing with money - only round the shown amount before showing it to user
|
||||
# - think about 10 * 0.0003 == 0?
|
||||
return float(new_amount)
|
||||
|
|
|
|||
Loading…
Reference in a new issue