diff --git a/nifty/operators/__init__.py b/nifty/operators/__init__.py
index 03b17ab55d2e58eacb3849d95a8209ab0acdee1f..0b01dcff4b182cad2b0a795f3af4d84b44c30f86 100644
--- a/nifty/operators/__init__.py
+++ b/nifty/operators/__init__.py
@@ -24,9 +24,10 @@ from .diagonal_operator import DiagonalOperator
 
 from .endomorphic_operator import EndomorphicOperator
 
-from .smoothing_operator import *
+from .fft_smoothing_operator import FFTSmoothingOperator
+from .direct_smoothing_operator import DirectSmoothingOperator
 
-from .fft_operator import *
+from .fft_operator import FFTOperator
 
 from .invertible_operator_mixin import InvertibleOperatorMixin
 
diff --git a/nifty/operators/composed_operator/composed_operator.py b/nifty/operators/composed_operator.py
similarity index 98%
rename from nifty/operators/composed_operator/composed_operator.py
rename to nifty/operators/composed_operator.py
index f4a38a02fe0ba0ac7585069528a0db74f310acb4..aacc9172db30e27f6374bdfb317c54452af9c1de 100644
--- a/nifty/operators/composed_operator/composed_operator.py
+++ b/nifty/operators/composed_operator.py
@@ -17,8 +17,8 @@
 # and financially supported by the Studienstiftung des deutschen Volkes.
 
 from builtins import range
-from ..linear_operator import LinearOperator
-from ... import DomainTuple
+from .linear_operator import LinearOperator
+from .. import DomainTuple
 
 class ComposedOperator(LinearOperator):
     """ NIFTY class for composed operators.
diff --git a/nifty/operators/composed_operator/__init__.py b/nifty/operators/composed_operator/__init__.py
deleted file mode 100644
index 4f1dd1888300755722f1bcde4803b11c4c851c5b..0000000000000000000000000000000000000000
--- a/nifty/operators/composed_operator/__init__.py
+++ /dev/null
@@ -1,19 +0,0 @@
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-# Copyright(C) 2013-2017 Max-Planck-Society
-#
-# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
-# and financially supported by the Studienstiftung des deutschen Volkes.
-
-from .composed_operator import ComposedOperator
diff --git a/nifty/operators/diagonal_operator/diagonal_operator.py b/nifty/operators/diagonal_operator.py
similarity index 96%
rename from nifty/operators/diagonal_operator/diagonal_operator.py
rename to nifty/operators/diagonal_operator.py
index a187c701499e174a8f04469f094aca841dbd936d..c830da847a0e8a0331f685ad4c171f4269cffb12 100644
--- a/nifty/operators/diagonal_operator/diagonal_operator.py
+++ b/nifty/operators/diagonal_operator.py
@@ -19,11 +19,10 @@
 from __future__ import division
 from builtins import range
 import numpy as np
-
-from ...field import Field
-from ...domain_tuple import DomainTuple
-from ..endomorphic_operator import EndomorphicOperator
-from ...nifty_utilities import cast_iseq_to_tuple
+from ..field import Field
+from ..domain_tuple import DomainTuple
+from .endomorphic_operator import EndomorphicOperator
+from ..nifty_utilities import cast_iseq_to_tuple
 
 class DiagonalOperator(EndomorphicOperator):
     """ NIFTY class for diagonal operators.
diff --git a/nifty/operators/diagonal_operator/__init__.py b/nifty/operators/diagonal_operator/__init__.py
deleted file mode 100644
index e8aa4e5a4051951acf52997a2d54b785c259fc6d..0000000000000000000000000000000000000000
--- a/nifty/operators/diagonal_operator/__init__.py
+++ /dev/null
@@ -1,19 +0,0 @@
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-# Copyright(C) 2013-2017 Max-Planck-Society
-#
-# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
-# and financially supported by the Studienstiftung des deutschen Volkes.
-
-from .diagonal_operator import DiagonalOperator
diff --git a/nifty/operators/smoothing_operator/direct_smoothing_operator.py b/nifty/operators/direct_smoothing_operator.py
similarity index 96%
rename from nifty/operators/smoothing_operator/direct_smoothing_operator.py
rename to nifty/operators/direct_smoothing_operator.py
index 8a99b2368d9f97543e82b7c7c20fe41e19b40502..67ae674e9c84197bdde19c57994a57ec5df3387e 100644
--- a/nifty/operators/smoothing_operator/direct_smoothing_operator.py
+++ b/nifty/operators/direct_smoothing_operator.py
@@ -4,9 +4,9 @@ from __future__ import division
 from builtins import range
 import numpy as np
 
-from ..endomorphic_operator import EndomorphicOperator
-from ... import nifty_utilities as utilities
-from ... import Field, DomainTuple
+from .endomorphic_operator import EndomorphicOperator
+from .. import nifty_utilities as utilities
+from .. import Field, DomainTuple
 
 
 class DirectSmoothingOperator(EndomorphicOperator):
diff --git a/nifty/operators/endomorphic_operator/endomorphic_operator.py b/nifty/operators/endomorphic_operator.py
similarity index 98%
rename from nifty/operators/endomorphic_operator/endomorphic_operator.py
rename to nifty/operators/endomorphic_operator.py
index 9e75ef2715c5f71c1d17e2833e945f15e2f81680..dafb5add7e7de35dd925d2d5f103b8457a1f118c 100644
--- a/nifty/operators/endomorphic_operator/endomorphic_operator.py
+++ b/nifty/operators/endomorphic_operator.py
@@ -17,8 +17,7 @@
 # and financially supported by the Studienstiftung des deutschen Volkes.
 
 import abc
-
-from ..linear_operator import LinearOperator
+from .linear_operator import LinearOperator
 
 
 class EndomorphicOperator(LinearOperator):
diff --git a/nifty/operators/endomorphic_operator/__init__.py b/nifty/operators/endomorphic_operator/__init__.py
deleted file mode 100644
index 87aaca6107d8c9b19318b68f59e4bd5cc4fd3eec..0000000000000000000000000000000000000000
--- a/nifty/operators/endomorphic_operator/__init__.py
+++ /dev/null
@@ -1,19 +0,0 @@
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-# Copyright(C) 2013-2017 Max-Planck-Society
-#
-# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
-# and financially supported by the Studienstiftung des deutschen Volkes.
-
-from .endomorphic_operator import EndomorphicOperator
diff --git a/nifty/operators/fft_operator/fft_operator.py b/nifty/operators/fft_operator.py
similarity index 97%
rename from nifty/operators/fft_operator/fft_operator.py
rename to nifty/operators/fft_operator.py
index b3bc0bd40acba6af60cb8355523b8cef733c4331..f4c82338fc61b84047c84d9ce61a8551c1c82b23 100644
--- a/nifty/operators/fft_operator/fft_operator.py
+++ b/nifty/operators/fft_operator.py
@@ -16,10 +16,10 @@
 # NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
 # and financially supported by the Studienstiftung des deutschen Volkes.
 
-from ... import Field, DomainTuple, nifty_utilities as utilities
-from ...spaces import RGSpace, GLSpace, HPSpace, LMSpace
+from .. import Field, DomainTuple, nifty_utilities as utilities
+from ..spaces import RGSpace, GLSpace, HPSpace, LMSpace
 
-from ..linear_operator import LinearOperator
+from .linear_operator import LinearOperator
 from .fft_operator_support import RGRGTransformation,\
                                   LMGLTransformation,\
                                   LMHPTransformation,\
diff --git a/nifty/operators/fft_operator/__init__.py b/nifty/operators/fft_operator/__init__.py
deleted file mode 100644
index cea86f72dc46b3507922dd8584753bb94bd2dd03..0000000000000000000000000000000000000000
--- a/nifty/operators/fft_operator/__init__.py
+++ /dev/null
@@ -1,19 +0,0 @@
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-# Copyright(C) 2013-2017 Max-Planck-Society
-#
-# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
-# and financially supported by the Studienstiftung des deutschen Volkes.
-
-from .fft_operator import FFTOperator
diff --git a/nifty/operators/fft_operator/fft_operator_support.py b/nifty/operators/fft_operator_support.py
similarity index 98%
rename from nifty/operators/fft_operator/fft_operator_support.py
rename to nifty/operators/fft_operator_support.py
index bb14e993cddc3b01bb50044c06592bb03eb1ed93..8113ac19ca4cffc3541f45d678e1eff8131a90a5 100644
--- a/nifty/operators/fft_operator/fft_operator_support.py
+++ b/nifty/operators/fft_operator_support.py
@@ -18,8 +18,8 @@
 
 from __future__ import division
 import numpy as np
-from ... import nifty_utilities as utilities
-from ...low_level_library import hartley
+from .. import nifty_utilities as utilities
+from ..low_level_library import hartley
 
 class Transformation(object):
     def __init__(self, domain, codomain):
diff --git a/nifty/operators/smoothing_operator/fft_smoothing_operator.py b/nifty/operators/fft_smoothing_operator.py
similarity index 94%
rename from nifty/operators/smoothing_operator/fft_smoothing_operator.py
rename to nifty/operators/fft_smoothing_operator.py
index 3384c26a755ed313fc330592e1ae0ca9ed89aa47..4e8edd2fb70f9905adc394361ca362f313a9797e 100644
--- a/nifty/operators/smoothing_operator/fft_smoothing_operator.py
+++ b/nifty/operators/fft_smoothing_operator.py
@@ -3,9 +3,9 @@
 from builtins import range
 import numpy as np
 
-from ..endomorphic_operator import EndomorphicOperator
-from ..fft_operator import FFTOperator
-from ... import DomainTuple
+from .endomorphic_operator import EndomorphicOperator
+from .fft_operator import FFTOperator
+from .. import DomainTuple
 
 class FFTSmoothingOperator(EndomorphicOperator):
     def __init__(self, domain, sigma, space=None):
diff --git a/nifty/operators/invertible_operator_mixin/invertible_operator_mixin.py b/nifty/operators/invertible_operator_mixin.py
similarity index 98%
rename from nifty/operators/invertible_operator_mixin/invertible_operator_mixin.py
rename to nifty/operators/invertible_operator_mixin.py
index 3b0454ca15bed85bec1d7adc415610a9694995ce..329ca07dc91652d9a40dd935dc269f40e77d7c60 100644
--- a/nifty/operators/invertible_operator_mixin/invertible_operator_mixin.py
+++ b/nifty/operators/invertible_operator_mixin.py
@@ -17,8 +17,8 @@
 # and financially supported by the Studienstiftung des deutschen Volkes.
 
 from builtins import object
-from ...energies import QuadraticEnergy
-from ...field import Field
+from ..energies import QuadraticEnergy
+from ..field import Field
 
 
 class InvertibleOperatorMixin(object):
diff --git a/nifty/operators/invertible_operator_mixin/__init__.py b/nifty/operators/invertible_operator_mixin/__init__.py
deleted file mode 100644
index 1785cdbf13d276da0960488accfaa9660c05ed0f..0000000000000000000000000000000000000000
--- a/nifty/operators/invertible_operator_mixin/__init__.py
+++ /dev/null
@@ -1,19 +0,0 @@
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-# Copyright(C) 2013-2017 Max-Planck-Society
-#
-# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
-# and financially supported by the Studienstiftung des deutschen Volkes.
-
-from .invertible_operator_mixin import InvertibleOperatorMixin
diff --git a/nifty/operators/laplace_operator/laplace_operator.py b/nifty/operators/laplace_operator.py
similarity index 95%
rename from nifty/operators/laplace_operator/laplace_operator.py
rename to nifty/operators/laplace_operator.py
index eb0062bbcc36278c721fdf92b32444cf8cb92b0e..ac5cc90067dfc9c5e87697c3bba5e9b8f27932f2 100644
--- a/nifty/operators/laplace_operator/laplace_operator.py
+++ b/nifty/operators/laplace_operator.py
@@ -17,11 +17,11 @@
 # and financially supported by the Studienstiftung des deutschen Volkes.
 
 import numpy as np
-from ...field import Field
-from ...spaces.power_space import PowerSpace
-from ..endomorphic_operator import EndomorphicOperator
-from ... import DomainTuple
-from ... import nifty_utilities as utilities
+from ..field import Field
+from ..spaces.power_space import PowerSpace
+from .endomorphic_operator import EndomorphicOperator
+from .. import DomainTuple
+from .. import nifty_utilities as utilities
 
 
 class LaplaceOperator(EndomorphicOperator):
diff --git a/nifty/operators/laplace_operator/__init__.py b/nifty/operators/laplace_operator/__init__.py
deleted file mode 100644
index 61427ae4fa1061209d0e6ad1a10bae7b931c5f46..0000000000000000000000000000000000000000
--- a/nifty/operators/laplace_operator/__init__.py
+++ /dev/null
@@ -1,3 +0,0 @@
-# -*- coding: utf-8 -*-
-
-from .laplace_operator import LaplaceOperator
diff --git a/nifty/operators/linear_operator/linear_operator.py b/nifty/operators/linear_operator.py
similarity index 98%
rename from nifty/operators/linear_operator/linear_operator.py
rename to nifty/operators/linear_operator.py
index cc0b225fff681798446192dfaaa1af78b3b2a3be..e1af3e810816ddd5ae78b901effb375a058a0bec 100644
--- a/nifty/operators/linear_operator/linear_operator.py
+++ b/nifty/operators/linear_operator.py
@@ -18,10 +18,9 @@
 
 from builtins import str
 import abc
-from ...nifty_meta import NiftyMeta
-
-from ...field import Field
-from ... import nifty_utilities as utilities
+from ..nifty_meta import NiftyMeta
+from ..field import Field
+from .. import nifty_utilities as utilities
 from future.utils import with_metaclass
 
 
diff --git a/nifty/operators/linear_operator/__init__.py b/nifty/operators/linear_operator/__init__.py
deleted file mode 100644
index b1a31fde720818abd6460999208e5f945a04a783..0000000000000000000000000000000000000000
--- a/nifty/operators/linear_operator/__init__.py
+++ /dev/null
@@ -1,19 +0,0 @@
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-# Copyright(C) 2013-2017 Max-Planck-Society
-#
-# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
-# and financially supported by the Studienstiftung des deutschen Volkes.
-
-from .linear_operator import LinearOperator
diff --git a/nifty/operators/response_operator/response_operator.py b/nifty/operators/response_operator.py
similarity index 92%
rename from nifty/operators/response_operator/response_operator.py
rename to nifty/operators/response_operator.py
index 863b19ca99e001219a99f7efbf90c40f90a561c2..976d9e3d32575132c2b836a416f57555bfb0be93 100644
--- a/nifty/operators/response_operator/response_operator.py
+++ b/nifty/operators/response_operator.py
@@ -1,11 +1,11 @@
 from builtins import range
-from ... import Field,\
-                FieldArray,\
-                DomainTuple
-from ..linear_operator import LinearOperator
-from ..smoothing_operator import FFTSmoothingOperator
-from ..composed_operator import ComposedOperator
-from ..diagonal_operator import DiagonalOperator
+from .. import Field,\
+               FieldArray,\
+               DomainTuple
+from .linear_operator import LinearOperator
+from .fft_smoothing_operator import FFTSmoothingOperator
+from .composed_operator import ComposedOperator
+from .diagonal_operator import DiagonalOperator
 
 
 class ResponseOperator(LinearOperator):
diff --git a/nifty/operators/response_operator/__init__.py b/nifty/operators/response_operator/__init__.py
deleted file mode 100644
index f69488116d05ae1723f484bc51c329a1859cecb5..0000000000000000000000000000000000000000
--- a/nifty/operators/response_operator/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-from .response_operator import ResponseOperator
diff --git a/nifty/operators/smoothing_operator/__init__.py b/nifty/operators/smoothing_operator/__init__.py
deleted file mode 100644
index 05acc94495c66887cd8db51e74089fe972ad9b6e..0000000000000000000000000000000000000000
--- a/nifty/operators/smoothing_operator/__init__.py
+++ /dev/null
@@ -1,20 +0,0 @@
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-# Copyright(C) 2013-2017 Max-Planck-Society
-#
-# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
-# and financially supported by the Studienstiftung des deutschen Volkes.
-
-from .fft_smoothing_operator import FFTSmoothingOperator
-from .direct_smoothing_operator import  DirectSmoothingOperator
diff --git a/nifty/operators/smoothness_operator/smoothness_operator.py b/nifty/operators/smoothness_operator.py
similarity index 92%
rename from nifty/operators/smoothness_operator/smoothness_operator.py
rename to nifty/operators/smoothness_operator.py
index 9aa01c99a07ec1ee591164aa1e3ec72196a17b73..613d5b5d622a45e10884b6353c3e86bad214548e 100644
--- a/nifty/operators/smoothness_operator/smoothness_operator.py
+++ b/nifty/operators/smoothness_operator.py
@@ -1,7 +1,7 @@
-from ...spaces.power_space import PowerSpace
-from ..endomorphic_operator import EndomorphicOperator
-from ..laplace_operator import LaplaceOperator
-from ... import Field, DomainTuple
+from ..spaces.power_space import PowerSpace
+from .endomorphic_operator import EndomorphicOperator
+from .laplace_operator import LaplaceOperator
+from .. import Field, DomainTuple
 
 
 class SmoothnessOperator(EndomorphicOperator):
diff --git a/nifty/operators/smoothness_operator/__init__.py b/nifty/operators/smoothness_operator/__init__.py
deleted file mode 100644
index 24e0f1fdec49ae44ed261c4cf3ba59603b25aeed..0000000000000000000000000000000000000000
--- a/nifty/operators/smoothness_operator/__init__.py
+++ /dev/null
@@ -1,3 +0,0 @@
-# -*- coding: utf-8 -*-
-
-from .smoothness_operator import SmoothnessOperator