Remove direct dependency on decorators package

Closes #212

dwave_networkx/utils/decorators.py

@@ -17,7 +17,8 @@
 algorithms.
 """
 
-from decorator import decorator
+import functools
+import inspect
 
 import dwave_networkx as dnx
 
@@ -34,117 +35,42 @@ def binary_quadratic_model_sampler(which_args):
         `function_name(args, *kw)`. If more than one
         sampler is allowed, can be a list of locations.
 
-    Returns
-    -------
-    _binary_quadratic_model_sampler : function
-        Caller function that validates the sampler format. A sampler
-        is expected to have `sample_qubo` and `sample_ising` methods.
-        Alternatively, if no sampler is provided (or sampler is None),
-        the sampler set by the `set_default_sampler` function is provided to
-        the function.
-
-    Examples
-    --------
-    Decorate functions like this::
-
-        @binary_quadratic_model_sampler(1)
-        def maximal_matching(G, sampler, **sampler_args):
-            pass
-
-    This example validates two placeholder samplers, which return a correct
-    response only in the case of finding an independent set on a complete graph
-    (where one node is always an independent set), the first valid, the second
-    missing a method.
-
-    >>> import networkx as nx
-    >>> import dwave_networkx as dnx
-    >>> from  dwave_networkx.utils import decorators
-    >>> # Create two placeholder samplers
-    >>> class WellDefinedSampler:
-    ...     # an example sampler, only works for independent set on complete
-    ...     # graphs
-    ...     def __init__(self, name):
-    ...         self.name = name
-    ...     def sample_ising(self, h, J):
-    ...         sample = {v: -1 for v in h}
-    ...         sample[0] = 1  # set one node to true
-    ...         return [sample]
-    ...     def sample_qubo(self, Q):
-    ...         sample = {v: 0 for v in set().union(*Q)}
-    ...         sample[0] = 1  # set one node to true
-    ...         return [sample]
-    ...     def __str__(self):
-    ...         return self.name
-    ...
-    >>> class IllDefinedSampler:
-    ...     # an example sampler missing a `sample_qubo` method
-    ...     def __init__(self, name):
-    ...         self.name = name
-    ...     def sample_ising(self, h, J):
-    ...         sample = {v: -1 for v in h}
-    ...         sample[0] = 1  # set one node to true
-    ...         return [sample]
-    ...     def __str__(self):
-    ...         return self.name
-    ...
-    >>> sampler1 = WellDefinedSampler('sampler1')
-    >>> sampler2 = IllDefinedSampler('sampler2')
-    >>> # Define a placeholder independent-set function with the decorator
-    >>> @dnx.utils.binary_quadratic_model_sampler(1)
-    ... def independent_set(G, sampler, **sampler_args):
-    ...     Q = {(node, node): -1 for node in G}
-    ...     Q.update({edge: 2 for edge in G.edges})
-    ...     response = sampler.sample_qubo(Q, **sampler_args)
-    ...     sample = next(iter(response))
-    ...     return [node for node in sample if sample[node] > 0]
-    ...
-    >>> # Validate the samplers
-    >>> G = nx.complete_graph(5)
-    >>> independent_set(G, sampler1)
-    [0]
-    >>> independent_set(G, sampler2)  # doctest: +SKIP
-    ---------------------------------------------------------------------------
-    TypeError                                 Traceback (most recent call last)
-    <ipython-input-35-670b71b268c7> in <module>()
-    ----> 1 independent_set(G, IllDefinedSampler)
-    <decorator-gen-628> in independent_set(G, sampler, **sampler_args)
-    /usr/local/lib/python2.7/dist-packages/dwave_networkx/utils/decorators.pyc in _binary_quadratic_model_sampler(f, *args, **kw)
-         61
-         62             if not hasattr(sampler, "sample_qubo") or not callable(sampler.sample_qubo):
-    ---> 63                 raise TypeError("expected sampler to have a 'sample_qubo' method")
-         64             if not hasattr(sampler, "sample_ising") or not callable(sampler.sample_ising):
-         65                 raise TypeError("expected sampler to have a 'sample_ising' method")
-    TypeError: expected sampler to have a 'sample_qubo' method
-
     """
-    @decorator
-    def _binary_quadratic_model_sampler(f, *args, **kw):
-        # convert into a sequence if necessary
-        if isinstance(which_args, int):
-            iter_args = (which_args,)
-        else:
-            iter_args = iter(which_args)
-
-        # check each sampler for the correct methods
-        new_args = [arg for arg in args]
-        for idx in iter_args:
-            sampler = args[idx]
-
-            # if no sampler is provided, get the default sampler if it has
-            # been set
-            if sampler is None:
-                # this sampler has already been vetted
-                default_sampler = dnx.get_default_sampler()
-                if default_sampler is None:
-                    raise dnx.DWaveNetworkXMissingSampler('no default sampler set')
-                new_args[idx] = default_sampler
-                continue
-
-            if not hasattr(sampler, "sample_qubo") or not callable(sampler.sample_qubo):
-                raise TypeError("expected sampler to have a 'sample_qubo' method")
-            if not hasattr(sampler, "sample_ising") or not callable(sampler.sample_ising):
-                raise TypeError("expected sampler to have a 'sample_ising' method")
-
-        # now run the function and return the results
-        return f(*new_args, **kw)
-    return _binary_quadratic_model_sampler
+    def decorator(f):
+        @functools.wraps(f)
+        def func(*args, **kwargs):
+            bound_arguments = inspect.signature(f).bind(*args, **kwargs)
+            bound_arguments.apply_defaults()
+
+            args = bound_arguments.args
+            kw = bound_arguments.kwargs
+
+            if isinstance(which_args, int):
+                iter_args = (which_args,)
+            else:
+                iter_args = iter(which_args)
+
+            # check each sampler for the correct methods
+            new_args = [arg for arg in args]
+            for idx in iter_args:
+                sampler = args[idx]
+
+                # if no sampler is provided, get the default sampler if it has
+                # been set
+                if sampler is None:
+                    # this sampler has already been vetted
+                    default_sampler = dnx.get_default_sampler()
+                    if default_sampler is None:
+                        raise dnx.DWaveNetworkXMissingSampler('no default sampler set')
+                    new_args[idx] = default_sampler
+                    continue
+
+                if not hasattr(sampler, "sample_qubo") or not callable(sampler.sample_qubo):
+                    raise TypeError("expected sampler to have a 'sample_qubo' method")
+                if not hasattr(sampler, "sample_ising") or not callable(sampler.sample_ising):
+                    raise TypeError("expected sampler to have a 'sample_ising' method")
+
+            # now run the function and return the results
+            return f(*new_args, **kw)
+        return func
+    return decorator

requirements.txt

@@ -1,3 +1,2 @@
 networkx==2.4
-decorator==4.3.0
 dimod==0.8.0

setup.py

@@ -30,7 +30,6 @@
             ]
 
 install_requires = ['networkx>=2.0,<3.0',
-                    'decorator>=4.1.0,<5.0.0',
                     'dimod>=0.8.0,!=0.10.0,!=0.10.1,!=0.10.2,!=0.10.3,!=0.10.4',
                     ]