diff --git a/nifty5/domain_tuple.py b/nifty5/domain_tuple.py
index cdbb0db10a58c26e122f591fe1c59c8c66bbcef7..547b8e51bdc51a89f742574481fa241123a7df26 100644
--- a/nifty5/domain_tuple.py
+++ b/nifty5/domain_tuple.py
@@ -18,9 +18,9 @@
 
 from __future__ import absolute_import, division, print_function
 
+from . import utilities
 from .compat import *
 from .domains.domain import Domain
-from . import utilities
 
 
 class DomainTuple(object):
diff --git a/nifty5/extra/energy_and_model_tests.py b/nifty5/extra/energy_and_model_tests.py
index 40b93a14447d7fef1648f6b1370d3ec0abbadc99..60022c10129a337759b102e3c6622e7518e56692 100644
--- a/nifty5/extra/energy_and_model_tests.py
+++ b/nifty5/extra/energy_and_model_tests.py
@@ -17,10 +17,12 @@
 # and financially supported by the Studienstiftung des deutschen Volkes.
 
 from __future__ import absolute_import, division, print_function
-from ..compat import *
+
 import numpy as np
-from ..sugar import from_random
+
+from ..compat import *
 from ..linearization import Linearization
+from ..sugar import from_random
 
 __all__ = ["check_value_gradient_consistency",
            "check_value_gradient_metric_consistency"]
diff --git a/nifty5/extra/operator_tests.py b/nifty5/extra/operator_tests.py
index e234d6e7ceffe493446a4149bd0264dab20dd83f..e2a83f981edb12b743c32b36ae7eea44f55cc2fe 100644
--- a/nifty5/extra/operator_tests.py
+++ b/nifty5/extra/operator_tests.py
@@ -17,10 +17,12 @@
 # and financially supported by the Studienstiftung des deutschen Volkes.
 
 from __future__ import absolute_import, division, print_function
-from ..compat import *
+
 import numpy as np
-from ..sugar import from_random
+
+from ..compat import *
 from ..field import Field
+from ..sugar import from_random
 
 __all__ = ["consistency_check"]
 
diff --git a/nifty5/library/amplitude_model.py b/nifty5/library/amplitude_model.py
index a404be0cb18f03d8bd3776fdf81e90a8cc07a299..1e0b10dbc7537538eddd13dcb79ad1866e568209 100644
--- a/nifty5/library/amplitude_model.py
+++ b/nifty5/library/amplitude_model.py
@@ -25,8 +25,8 @@ from ..domains.power_space import PowerSpace
 from ..domains.unstructured_domain import UnstructuredDomain
 from ..field import Field
 from ..multi_domain import MultiDomain
-from ..sugar import makeOp, sqrt
 from ..operators.operator import Operator
+from ..sugar import makeOp, sqrt
 
 
 def _ceps_kernel(dof_space, k, a, k0):
diff --git a/nifty5/library/correlated_fields.py b/nifty5/library/correlated_fields.py
index 3ff54c410ad5aae1dea41c278d8d1f630d5a8eec..78c428e7bb26d1614aefa4aa8e97a971992fc40c 100644
--- a/nifty5/library/correlated_fields.py
+++ b/nifty5/library/correlated_fields.py
@@ -21,11 +21,11 @@ from __future__ import absolute_import, division, print_function
 from ..compat import *
 from ..domain_tuple import DomainTuple
 from ..multi_domain import MultiDomain
+from ..operators.distributors import PowerDistributor
 from ..operators.domain_distributor import DomainDistributor
 from ..operators.harmonic_operators import HarmonicTransformOperator
-from ..operators.distributors import PowerDistributor
-from ..sugar import exp
 from ..operators.simple_linear_operators import FieldAdapter
+from ..sugar import exp
 
 
 def CorrelatedField(s_space, amplitude_model):
diff --git a/nifty5/library/inverse_gamma_model.py b/nifty5/library/inverse_gamma_model.py
index aa8292e3316d83874f7fbe21fcaaaf7bf349429f..9be2acce1a7b4aad7e292849034cca8cd10a60b0 100644
--- a/nifty5/library/inverse_gamma_model.py
+++ b/nifty5/library/inverse_gamma_model.py
@@ -22,9 +22,9 @@ import numpy as np
 from scipy.stats import invgamma, norm
 
 from ..compat import *
-from ..operators.operator import Operator
-from ..linearization import Linearization
 from ..field import Field
+from ..linearization import Linearization
+from ..operators.operator import Operator
 from ..sugar import makeOp
 
 
diff --git a/nifty5/minimization/descent_minimizers.py b/nifty5/minimization/descent_minimizers.py
index 9cbc92675e2218406bda8f9e1839ef0c0e63e176..0517bd8141abc228f3dead8e9cbcd4822efd696a 100644
--- a/nifty5/minimization/descent_minimizers.py
+++ b/nifty5/minimization/descent_minimizers.py
@@ -19,6 +19,7 @@
 from __future__ import absolute_import, division, print_function
 
 import numpy as np
+
 from ..compat import *
 from ..logger import logger
 from .line_search_strong_wolfe import LineSearchStrongWolfe
diff --git a/nifty5/minimization/energy_adapter.py b/nifty5/minimization/energy_adapter.py
index 1ee944ae996fcb95936342b164955717b9cb32ad..f85d2e9d8c215a034319949190a5d8f2c063633e 100644
--- a/nifty5/minimization/energy_adapter.py
+++ b/nifty5/minimization/energy_adapter.py
@@ -1,12 +1,10 @@
 from __future__ import absolute_import, division, print_function
 
 from ..compat import *
-from ..minimization.energy import Energy
 from ..linearization import Linearization
-from ..multi_field import MultiField
-from ..operators.scaling_operator import ScalingOperator
+from ..minimization.energy import Energy
 from ..operators.block_diagonal_operator import BlockDiagonalOperator
-import numpy as np
+from ..operators.scaling_operator import ScalingOperator
 
 
 class EnergyAdapter(Energy):
diff --git a/nifty5/minimization/scipy_minimizer.py b/nifty5/minimization/scipy_minimizer.py
index fbf2cf66d0b74db2585374ba086dc52b26922c39..df37006b21666fd2159b3796ab27bb6e6e962b76 100644
--- a/nifty5/minimization/scipy_minimizer.py
+++ b/nifty5/minimization/scipy_minimizer.py
@@ -19,15 +19,15 @@
 from __future__ import absolute_import, division, print_function
 
 import numpy as np
+
 from .. import dobj
 from ..compat import *
 from ..field import Field
-from ..multi_field import MultiField
-from ..domain_tuple import DomainTuple
 from ..logger import logger
+from ..multi_field import MultiField
+from ..utilities import iscomplextype
 from .iteration_controllers import IterationController
 from .minimizer import Minimizer
-from ..utilities import iscomplextype
 
 
 def _multiToArray(fld):
diff --git a/nifty5/multi_field.py b/nifty5/multi_field.py
index a3dd8cfbe22dbda60681bf9611335fd3511d9b35..5f6aa304a56b31a192295cc8118ba804e9ebaffe 100644
--- a/nifty5/multi_field.py
+++ b/nifty5/multi_field.py
@@ -20,10 +20,10 @@ from __future__ import absolute_import, division, print_function
 
 import numpy as np
 
+from . import utilities
 from .compat import *
 from .field import Field
 from .multi_domain import MultiDomain
-from . import utilities
 
 
 class MultiField(object):
diff --git a/nifty5/plotting/plot.py b/nifty5/plotting/plot.py
index 1c930fe130f71879991512b525784f90d14cedb0..915f84d7ef0549d0a16d261a6cc80c5aedf8cb9c 100644
--- a/nifty5/plotting/plot.py
+++ b/nifty5/plotting/plot.py
@@ -22,13 +22,13 @@ import os
 
 import numpy as np
 
+from .. import dobj
 from ..compat import *
-from ..field import Field
 from ..domains.gl_space import GLSpace
 from ..domains.hp_space import HPSpace
 from ..domains.power_space import PowerSpace
 from ..domains.rg_space import RGSpace
-from .. import dobj
+from ..field import Field
 
 # relevant properties:
 # - x/y size
diff --git a/nifty5/sugar.py b/nifty5/sugar.py
index b69e04d4bfa179577c8325b51d0c7e198e0367e6..39b7f718f5b3f9e2c14f08ac236ac9c308268c25 100644
--- a/nifty5/sugar.py
+++ b/nifty5/sugar.py
@@ -28,13 +28,12 @@ from .domain_tuple import DomainTuple
 from .domains.power_space import PowerSpace
 from .field import Field
 from .logger import logger
-from .operators.block_diagonal_operator import BlockDiagonalOperator
 from .multi_domain import MultiDomain
 from .multi_field import MultiField
+from .operators.block_diagonal_operator import BlockDiagonalOperator
 from .operators.diagonal_operator import DiagonalOperator
 from .operators.distributors import PowerDistributor
 
-
 __all__ = ['PS_field', 'power_analyze', 'create_power_operator',
            'create_harmonic_smoothing_operator', 'from_random',
            'full', 'from_global_data', 'from_local_data',
diff --git a/nifty5/utilities.py b/nifty5/utilities.py
index c1acc1bd5590e64db9eab6772bd8369a504a4a8e..9dc3ef836b9c1bdae5189551ebb0a513c8778acd 100644
--- a/nifty5/utilities.py
+++ b/nifty5/utilities.py
@@ -22,9 +22,9 @@ import collections
 from itertools import product
 
 import numpy as np
-from future.utils import with_metaclass
 import pyfftw
-from pyfftw.interfaces.numpy_fft import rfftn, fftn
+from future.utils import with_metaclass
+from pyfftw.interfaces.numpy_fft import fftn, rfftn
 
 from .compat import *