diff options
Diffstat (limited to 'cfetch/__init__.py')
| -rw-r--r-- | cfetch/__init__.py | 35 |
1 files changed, 27 insertions, 8 deletions
diff --git a/cfetch/__init__.py b/cfetch/__init__.py index 281555a..ad01e57 100644 --- a/cfetch/__init__.py +++ b/cfetch/__init__.py @@ -23,6 +23,12 @@ from requests import get __version__ = '5.2.0' +class NoSuchPairException(Exception): + pass + +class NoSuchKindException(Exception): + pass + ## A cryptocurrency exchange rate ticker. class Ticker(): ## Constructor for this class. @@ -47,9 +53,25 @@ class Ticker(): else: raise TypeError('pair cannot be {}'.format(type(pair))) - def _get_single_rate(self, a, b, amt, power, kind): + ## Gets the exchange rate between two currencies raised to a power. + # @param a The first currency. + # @param b The second currency. + # @param amt The number quantity of 'a' currency. + # @param power The power to which the calculation will be raised. + # @param kind The type of rate to calculate. + # @return The exchange rate between 'a' and 'b' currencies raised to + # 'power'. + def get_rate_pow(self, a, b, amt, power, kind): r = get(self.path + self.get_pair(a, b)) - res = self.get_pair_data(r, (a, b)) + + try: + res = self.get_pair_data(r, (a, b)) + except KeyError as e: + raise NoSuchPairException(str(e)) + + if kind not in res: + raise NoSuchKindException(kind) + return (float(res[kind]) ** power) * amt ## Calculates the exchange rate between two currencies. @@ -60,12 +82,9 @@ class Ticker(): # @return The exchange rate between 'a' and 'b' currencies. def get_rate(self, a, b, amt=1, kind='avg'): try: - return self._get_single_rate(a, b, amt, 1, kind) - except (KeyError, TypeError): - try: - return self._get_single_rate(b, a, amt, -1, kind) - except (KeyError, TypeError) as e: - raise ValueError(str(e)) # currency pair not found + return self.get_rate_pow(a, b, amt, 1, kind) + except NoSuchPairException: + return self.get_rate_pow(b, a, amt, -1, kind) _INDEX = { 'description': 0, |