support for positional arguments

README.md

@@ -109,6 +109,7 @@ There will be enhancements in the future to address this problem in a number of
 * Added support for the v2 API
 * Added local configuration (~/.etsy) to eliminate cutting & pasting of api keys.
 * Added client-side type checking for parameters.
+* Added support for positional arguments.
 * Added a test suite.
 * Added module to PyPI. 
 

etsy/_core.py

@@ -5,6 +5,7 @@ import urllib2
 from urllib import urlencode
 from ConfigParser import ConfigParser
 import os
+import re
 
 
 
@@ -65,8 +66,52 @@ class TypeChecker(object):
     def check_string(self, value):
         return isinstance(value, basestring), value
 
+
+
+
+class APIMethod(object):
+    def __init__(self, api, spec):
+        self.api = api
+        self.spec = spec
+        self.type_checker = self.api.type_checker
+        self.__doc__ = self.spec['description']
+        self.compiled = False
     
 
+    def __call__(self, *args, **kwargs):
+        if not self.compiled:
+            self.compile()
+        return self.invoke(*args, **kwargs)
+
+
+    def compile(self):
+        self.positionals = re.findall('{(.*)}', self.spec['uri'])
+        self.compiled = True
+
+
+    def invoke(self, *args, **kwargs):
+        if args and not self.positionals:
+            raise ValueError(
+                'Positional argument(s): %s provided, but this method does '
+                'not support them.' % (args,))
+
+        if len(args) > len(self.positionals):
+            raise ValueError('Too many positional arguments.')
+
+        for k, v in zip(self.positionals, args):
+            if k in kwargs:
+                raise ValueError(
+                    'Positional argument duplicated in kwargs: %s' % k)
+            kwargs[k] = v
+
+        for p in self.positionals:
+            if p not in kwargs:
+                raise ValueError("Required argument '%s' not provided." % p)
+
+        self.type_checker(self.spec, **kwargs)
+        return self.api._get(self.spec['uri'], **kwargs)
+
+
 
 
 class API(object):
@@ -94,7 +139,7 @@ class API(object):
         self._methods = dict([(m['name'], m) for m in ms])
 
         for method in ms:
-            self._create_method(method)
+            setattr(self, method['name'], APIMethod(self, method))
 
 
     def _get_method_table(self):
@@ -113,19 +158,6 @@ class API(object):
         return gs[self.api_version]
         
 
-    def _create_method(self, m):
-        def method(**kwargs):
-            return self._invoke(m, **kwargs)
-        method.__name__ = m['name']
-        method.__doc__ = m['description']
-        setattr(self, m['name'], method)
-
-
-    def _invoke(self, m, **kwargs):
-        self.type_checker(m, **kwargs)
-        return self._get(m['uri'], **kwargs)
-
-
     def _get_url(self, url):
         with closing(urllib2.urlopen(url)) as f:
             return f.read() 
@@ -135,7 +167,7 @@ class API(object):
         for k, v in kwargs.items():
             arg = '{%s}' % k
             if arg in url:
-                url = url.replace(arg, v)
+                url = url.replace(arg, str(v))
                 del kwargs[k]
 
         kwargs.update(dict(api_key=self.api_key))

test/test_core.py

@@ -24,7 +24,13 @@ class MockAPI(API):
                      'kind': 'string',
                      },
                  'type': 'int', 
-                 'description': 'test method.'}]
+                 'description': 'test method.'},
+                {'name': 'noPositionals',
+                 'uri': '/blah',
+                 'http_method': 'GET',
+                 'params': {'foo': 'int'},
+                 'type': 'int',
+                 'description': 'no pos arguments'}]
 
 
     def _get_url(self, url):
@@ -113,17 +119,18 @@ class CoreTests(Test):
 
 
     def test_unrecognized_kwarg(self):
-        msg = self.assertRaises(ValueError, self.api.testMethod, not_an_arg=1)
+        msg = self.assertRaises(ValueError, self.api.testMethod, 
+                                test_id=1, not_an_arg=1)
         self.assertEqual(msg, 'Unexpected argument: not_an_arg=1')
 
     
     def test_unknown_parameter_type_is_passed(self):
-        self.api.testMethod(blah=1)
+        self.api.testMethod(test_id=1, blah=1)
         self.assertEqual(self.last_query()['blah'], ['1'])
 
 
     def test_parameter_type_int(self):
-        self.api.testMethod(limit=5)
+        self.api.testMethod(test_id=1, limit=5)
         self.assertEqual(self.last_query()['limit'], ['5'])
 
 
@@ -131,43 +138,73 @@ class CoreTests(Test):
         return "Bad value for parameter %s of type '%s' - %s" % (name, t, v)
 
     def test_invalid_parameter_type_int(self):
-        msg = self.assertRaises(ValueError, self.api.testMethod, limit=5.6)
+        msg = self.assertRaises(ValueError, self.api.testMethod, 
+                                test_id=1, limit=5.6)
         self.assertEqual(msg, self.bad_value_msg('limit', 'int', 5.6))
 
 
     def test_parameter_type_float(self):
-        self.api.testMethod(buzz=42.1)
+        self.api.testMethod(test_id=1, buzz=42.1)
         self.assertEqual(self.last_query()['buzz'], ['42.1'])
 
 
     def test_invalid_parameter_type_float(self):
-        msg = self.assertRaises(ValueError, self.api.testMethod, buzz='x')
+        msg = self.assertRaises(ValueError, self.api.testMethod, 
+                                test_id=1, buzz='x')
         self.assertEqual(msg, self.bad_value_msg('buzz', 'float', 'x'))
 
     
     def test_int_accepted_as_float(self):
-        self.api.testMethod(buzz=3)
+        self.api.testMethod(test_id=1, buzz=3)
         self.assertEqual(self.last_query()['buzz'], ['3'])
 
         
     def test_parameter_type_enum(self):
-        self.api.testMethod(fizz='bar')
+        self.api.testMethod(test_id=1, fizz='bar')
         self.assertEqual(self.last_query()['fizz'], ['bar'])
 
 
     def test_invalid_parameter_type_enum(self):
-        msg = self.assertRaises(ValueError, self.api.testMethod, fizz='goo')
+        msg = self.assertRaises(ValueError, self.api.testMethod, 
+                                test_id=1, fizz='goo')
         self.assertEqual(msg, self.bad_value_msg(
                 'fizz', 'enum(foo, bar, baz)', 'goo'))
 
 
     def test_parameter_type_string(self):
-        self.api.testMethod(kind='blah')
+        self.api.testMethod(test_id=1, kind='blah')
         self.assertEqual(self.last_query()['kind'], ['blah'])
 
 
     def test_invalid_parameter_type_string(self):
-        msg = self.assertRaises(ValueError, self.api.testMethod, kind=Test)
+        msg = self.assertRaises(ValueError, self.api.testMethod, 
+                                test_id=1, kind=Test)
         self.assertEqual(msg, self.bad_value_msg('kind', 'string', Test))
 
 
+    def test_url_arguments_work_positionally(self):
+        self.api.testMethod('foo')
+        self.assertEqual(self.api.last_url, 
+                         'http://host/test/foo?api_key=apikey')
+
+
+    def test_method_with_no_positionals_doesnt_accept_them(self):
+        msg = self.assertRaises(ValueError, self.api.noPositionals, 1, 2)
+        self.assertEqual('Positional argument(s): (1, 2) provided, but this '
+                         'method does not support them.', msg)
+
+    
+    def test_too_many_positionals(self):
+        msg = self.assertRaises(ValueError, self.api.testMethod, 1, 2)
+        self.assertEqual('Too many positional arguments.', msg)
+
+
+    def test_positional_argument_not_provided(self):
+        msg = self.assertRaises(ValueError, self.api.testMethod)
+        self.assertEqual("Required argument 'test_id' not provided.", msg)
+
+
+    def test_positional_argument_duplicated_in_kwargs(self):
+        msg = self.assertRaises(ValueError, self.api.testMethod, 1, test_id=2)
+        self.assertEqual('Positional argument duplicated in kwargs: test_id', 
+                         msg)