exchange CLI finished and functions made more robust

salamanca/cli.py

@@ -41,21 +41,40 @@ def download_wb(log=False, overwrite=False, **kwargs):
 #
 
 def exchange_cli(parser):
-    amt = 'quantity of currency'
-    parser.add_argument('amt', help=amt, default=1.0)
+    amt = 'quantity of currency (default: 1.0)'
+    parser.add_argument('-x', '--amt', help=amt, default=1.0)
+    units = "units in which to do conversion [MER or PPP] (default: MER)"
+    parser.add_argument('-u', '--units', help=units, default='MER')
+    meth = "method to use to do conversion [deflator or cpi] (default: deflator)"
+    parser.add_argument('-m', '--meth', help=meth, default='deflator')
+
     required = parser.add_argument_group('required arguments')
-    _from = '(iso, year) a 3-letter ISO code for the origin country and origin year'
-    required.add_argument('-f', '--from', help=_from, nargs=2, required=True)
-    _to = '(iso, year) a 3-letter ISO code for the destination country and destination year'
-    required.add_argument('-t', '--to', help=_to, nargs=2, required=True)
+    _from = """
+    ISO: 3-letter ISO code for the origin country, YEAR: origin year
+    """
+    required.add_argument('-f', '--from', help=_from,
+                          nargs=2, metavar=('ISO', 'YEAR'), required=True)
+    _to = """
+    ISO: 3-letter ISO code for the destination country, YEAR: destination year
+    """
+    required.add_argument('-t', '--to', help=_to,
+                          nargs=2, metavar=('ISO', 'YEAR'), required=True)
 
 
-def exchange(*args, **kwargs):
-    kwargs.pop('command')
-    amt = kwargs.pop('amt', 1)
-    xlator = currency.Translator()
-    return xlator.exchange(amt, **kwargs)
+def exchange(**kwargs):
+    amt = kwargs['amt']
+    fromiso, fromyr = kwargs['from']
+    toiso, toyr = kwargs['to']
+    units = kwargs['units']
+    inflation_method = kwargs['meth']
 
+    xlator = currency.Translator()
+    ret = xlator.exchange(amt,
+                          fromiso=fromiso, fromyr=fromyr,
+                          toiso=toiso, toyr=toyr,
+                          units=units, inflation_method=inflation_method)
+    print(ret)
+    return ret
 
 COMMANDS['exchange'] = (
     """Exchange currency from one country/year to another.""",
@@ -77,7 +96,10 @@ def main():
     for cmd in COMMANDS:
         cli_help = COMMANDS[cmd][0]
         cli_func = COMMANDS[cmd][1]
-        subparser = subparsers.add_parser(cmd, help=cli_help)
+        subparser = subparsers.add_parser(
+            cmd,
+            help=cli_help,
+        )
         cli_func(subparser)
 
     args = parser.parse_args()

salamanca/currency.py

@@ -24,7 +24,7 @@ def __init__(self):
         self._xr = wb.to_wide(wb.exchange_rate()).set_index('country')
         self._ppp_to_mer = wb.to_wide(wb.ppp_to_mer()).set_index('country')
 
-    def inflation(self, iso, fromyr, toyr, method=None):
+    def inflation(self, iso, fromyr, toyr, method='deflator'):
         """Calculate inflation for a country
 
         Parameters
@@ -38,7 +38,7 @@ def inflation(self, iso, fromyr, toyr, method=None):
         method: str
             one of: cpi, deflator (default: deflator)
         """
-        method = method or 'deflator'
+        method = method.lower()
         df = self._cpi if method == 'cpi' else self._gdp_deflator
         x = df.loc[iso][toyr] / df.loc[iso][fromyr]
         if np.isnan(x):
@@ -51,7 +51,7 @@ def inflation(self, iso, fromyr, toyr, method=None):
     def exchange(self, x, iso=None, yr=None, units='MER',
                  fromiso=None, fromyr=None,
                  toiso=None, toyr=None,
-                 inusd=False, inflation_method=None):
+                 inusd=False, inflation_method='deflator'):
         """Exchange currency from one country/year to another.
 
         Parameters
@@ -79,10 +79,16 @@ def exchange(self, x, iso=None, yr=None, units='MER',
             the argument to provide to `inflation()`
         """
         fromiso = fromiso or iso
+        fromiso = fromiso.upper()
         fromyr = fromyr or yr
+        fromyr = int(fromyr)
 
         toiso = toiso or 'USA'
+        toiso = toiso.upper()
         toyr = toyr or yr
+        toyr = int(toyr)
+
+        units = units.upper()
 
         # is using special inusd option, do full calculation and return
         if inusd:

tests/test_currency.py

@@ -150,11 +150,16 @@ def test_aut_2005_2010_usd_ppp():
 
 
 def test_cli():
-    obs = cli.exchange(command='exchange', amt=20, iso='AUT', fromyr=2005,
-                       toyr=2010, inusd=True, units='PPP')
-    exp = 20 * (xr_aut_2005 * ppp_to_mer_aut_2005) * \
-        (100. / gdef_aut_2005) / \
-        (xr_aut_2010 * ppp_to_mer_aut_2010)
+    kwargs = {
+        'amt': 20,
+        'from': ('CAN', '2005'),
+        'to': ('AUT', '2010'),
+        'units': 'PPP',
+        'meth': 'deflator',
+    }
+    obs = cli.exchange(**kwargs)
+    exp = 20 * (xr_aut_2005 / xr_can_2005) / (gdef_aut_2005 / 100.)
+    exp *= ppp_to_mer_aut_2005 / ppp_to_mer_can_2005
     assert_almost_equal(obs, exp)