currency_converter.py

currency_converter.py

#!/usr/bin/env python3
#
# Prerequisites:
#   Install globally:           `python3 -m pip install requests`
#   Install locally via pipenv: `pipenv install requests`
#
# Version: v1.0.3
# License: MIT License
#          Copyright (c) 2020-2021 Hunter T. (StrangeRanger)
#
########################################################################################
"""
Using the API (https://api.exchangeratesapi.io/latest), this script converts one
currency into another.
"""
####[ Imports ]#########################################################################


import requests


####[ Variables ]#######################################################################


RED = "\033[1;31m"
DEFCLR = "\033[0m"
request = requests.get("https://api.exchangeratesapi.io/latest").json()
base_value = 0.00
non_base_value = 0.00


####[ Functions ]#######################################################################


def check_valid_currency(currency, base_currency=False):
    """Check if the given currency exists in the json retrieved through the API, then
    modifies 'request' and 'base_value'/'non_base_value' accordingly.

    Parameters
    ----------
    currency : str
        Shorthanded currency name (i.e. USD).
    base_currency : bool, optional
        True if the actions are being performed for the base currency, False otherwise.

    Returns
    -------
    bool
        True if the input is valid, False otherwise.
    """
    global request
    global base_value
    global non_base_value

    try:
        if base_currency:
            if request["rates"][currency]:
                request = requests.get(
                    "https://api.exchangeratesapi.io/latest?base={}".format(base)
                ).json()
                base_value = request["rates"][currency]
                return True
        else:
            if request["rates"][currency]:
                non_base_value = request["rates"][currency]
                return True
    ## REASON: Occurs if the user enters an invalid currency.
    except KeyError:
        return False


####[ Main ]############################################################################


print(
    "IMPORTANT NOTES:\n1) When entering a currency, enter it's short handed name (i.e."
    " US Dollar = USD, Japanese yen = JPY, etc."
)
print(
    "2) All available currencies (as of 2020-12-7):\n"
    "    AUD = Australian dollar   |  BGN = Bulgarian lev\n"
    "    BRL = Brazilian real      |  CAD = Canadian dollar\n"
    "    CHF = Swiss franc         |  CNY = Chinese yuan renminbi\n"
    "    CZK = Czech koruna        |  DKK = Danish krone\n"
    "    GBP = Pound sterling      |  HKD = Hong Kong dollar\n"
    "    HRK = Croatian kuna       |  HUF = Hungarian forint\n"
    "    ILS = Israeli shekel      |  INR = Indian rupee\n"
    "    ISK = Icelandic krona     |  JPY = Japanese yen\n"
    "    KRW = South Korean won    |  MXN = Mexican peso\n"
    "    MYR = Malaysian ringgit   |  NOK = Norwegian krone\n"
    "    NZD = New Zealand dollar  |  PHP = Philippine peso\n"
    "    PLN = Polish zloty        |  RON = Romanian leu\n"
    "    RUB = Russian rouble      |  SEK = Swedish krona\n"
    "    SGD = Singapore dollar    |  THB = Thai baht\n"
    "    TRY = Turkish lira        |  USD = US dollar\n"
    "    ZAR = South African rand\n"
)

while True:
    base = input("Enter base currency to be converted: ").upper()
    if check_valid_currency(base, base_currency=True):
        print("")
        break
    print("{}Invalid input: Please enter a valid currency{}".format(RED, DEFCLR))

while True:
    non_base = input("Enter currency to convert the base currency to: ").upper()
    if check_valid_currency(non_base):
        print("")
        break
    print("{}Invalid input: Please enter a valid currency{}".format(RED, DEFCLR))

print("Note: Currency is rounded to two decimals")
while True:
    try:
        amount = round(float(input("Enter an amount to be converted: ")), 2)
        print("")
        break
    except ValueError:
        print(
            "{}Invalid input: Only numbers are accepted as input{}".format(RED, DEFCLR)
        )

print(
    "Conversion Rate\n{}: {}\n{}: {}\n".format(
        base, base_value, non_base, non_base_value
    )
)
print(
    "Note: Rounded to two decimals\nConverted currency approximate: {} {}".format(
        round(amount * non_base_value, 2), non_base
    )
)