Merge pull request Qiskit#23 from gadial/readout_mitigator

Attempting to fix cyclic dependancy error

qiskit/result/mitigation/base_readout_mitigator.py

@@ -16,7 +16,8 @@
 from abc import ABC, abstractmethod
 from typing import Optional, List, Iterable, Tuple, Union, Callable
 import numpy as np
-from .. import Counts, QuasiDistribution
+from ..distributions.quasi import QuasiDistribution
+from ..counts import Counts
 
 
 class BaseReadoutMitigator(ABC):

qiskit/result/mitigation/correlated_readout_mitigator.py

@@ -16,8 +16,9 @@
 from typing import Optional, List, Tuple, Iterable, Callable, Union
 import numpy as np
 
-from .. import Counts, QuasiDistribution
 from qiskit import QiskitError
+from ..distributions.quasi import QuasiDistribution
+from ..counts import Counts
 from .base_readout_mitigator import BaseReadoutMitigator
 from .utils import counts_probability_vector, z_diagonal, str2diag
 

qiskit/result/mitigation/local_readout_mitigator.py

@@ -19,8 +19,9 @@
 
 from qiskit.providers import Backend
 from qiskit.providers.models import BackendProperties
-from .. import Counts, QuasiDistribution
 from qiskit.exceptions import QiskitError
+from ..distributions.quasi import QuasiDistribution
+from ..counts import Counts
 from .base_readout_mitigator import BaseReadoutMitigator
 from .utils import counts_probability_vector, z_diagonal, str2diag
 

qiskit/result/mitigation/utils.py

@@ -18,7 +18,8 @@
 import numpy as np
 
 from qiskit.exceptions import QiskitError
-from .. import Counts, marginal_counts
+from ..utils import marginal_counts
+from ..counts import Counts
 
 logger = logging.getLogger(__name__)