From f773da10ae21fae1d65eb8e268ca5e2431fe54ef Mon Sep 17 00:00:00 2001
From: Julian Hammer <julian.hammer@fau.de>
Date: Wed, 6 Dec 2017 17:15:49 +0100
Subject: [PATCH] Removed legacy imports and six and changed shebang python3

---
 .travis.yml                                   |  1 -
 kerncraft/cacheprediction.py                  |  8 +--
 kerncraft/cachetile.py                        | 11 +---
 kerncraft/iaca.py                             | 11 +---
 kerncraft/iaca_get.py                         |  6 +--
 kerncraft/intervals.py                        |  2 +-
 kerncraft/kerncraft.py                        | 51 ++++++++-----------
 kerncraft/kernel.py                           | 20 ++------
 kerncraft/likwid_bench_auto.py                | 14 +----
 kerncraft/machinemodel.py                     |  6 +--
 kerncraft/models/benchmark.py                 | 20 ++------
 kerncraft/models/ecm.py                       | 13 ++---
 kerncraft/models/layer_condition.py           | 35 +------------
 kerncraft/models/roofline.py                  |  7 +--
 kerncraft/picklemerge.py                      |  6 +--
 kerncraft/prefixedunit.py                     | 13 ++---
 kerncraft/roofline-plot.py                    |  7 +--
 likwid-counter-packing.py                     |  7 +--
 setup.py                                      |  7 +--
 tests/all_tests.py                            |  2 +-
 tests/test_files/dummy_likwid/likwid-bench    |  4 +-
 tests/test_files/dummy_likwid/likwid-perfctr  |  4 +-
 tests/test_files/dummy_likwid/likwid-topology |  4 +-
 tests/test_intervals.py                       |  4 +-
 tests/test_kerncraft.py                       | 37 ++++++--------
 tests/test_kernel.py                          | 18 +------
 tests/test_layer_condition.py                 | 11 +---
 tests/test_likwid_bench_auto.py               | 17 +------
 tox.ini                                       |  2 +-
 29 files changed, 76 insertions(+), 272 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 8923584..12d60f8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,5 @@
 language: python
 python:
-- '2.7'
 - '3.4'
 - '3.5'
 - '3.6'
diff --git a/kerncraft/cacheprediction.py b/kerncraft/cacheprediction.py
index 98ae734..67e3d4d 100755
--- a/kerncraft/cacheprediction.py
+++ b/kerncraft/cacheprediction.py
@@ -1,11 +1,5 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Cache prediction interface classes are gathered in this module."""
-
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
 from itertools import chain
 
 import sympy
diff --git a/kerncraft/cachetile.py b/kerncraft/cachetile.py
index 1e00f5e..dd93307 100755
--- a/kerncraft/cachetile.py
+++ b/kerncraft/cachetile.py
@@ -1,15 +1,8 @@
-#!/usr/bin/env python
-
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
+#!/usr/bin/env python3
 import argparse
 import sys
 
 import sympy
-import six
 from ruamel import yaml
 
 from . import models
@@ -55,7 +48,7 @@ def run(parser, args):
     machine = MachineModel(args.machine.name)
 
     # process kernel description
-    description = six.text_type(args.description_file.read())
+    description = str(args.description_file.read())
     kernel = KernelDescription(yaml.load(description))
 
     # Add constants from define arguments
diff --git a/kerncraft/iaca.py b/kerncraft/iaca.py
index b50d9da..afacfb9 100755
--- a/kerncraft/iaca.py
+++ b/kerncraft/iaca.py
@@ -1,22 +1,13 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Helper functions to instumentalize assembly code for and analyze with IACA."""
-from __future__ import print_function
-from __future__ import absolute_import
-
 # Version check
 import sys
-if sys.version_info[0] == 2 and sys.version_info < (2, 7) or \
-        sys.version_info[0] == 3 and sys.version_info < (3, 4):
-    print("Must use python 2.7 or 3.4 and greater.", file=sys.stderr)
-    sys.exit(1)
-
 import re
 import subprocess
 import os
 from copy import copy
 
 from distutils.spawn import find_executable
-from six.moves import input
 
 from kerncraft import iaca_get
 
diff --git a/kerncraft/iaca_get.py b/kerncraft/iaca_get.py
index 47511bf..299a9f5 100755
--- a/kerncraft/iaca_get.py
+++ b/kerncraft/iaca_get.py
@@ -1,7 +1,4 @@
-#!/usr/bin/env python
-from __future__ import print_function
-from __future__ import absolute_import
-
+#!/usr/bin/env python3
 import os
 import sys
 import stat
@@ -11,7 +8,6 @@
 import tempfile
 import shutil
 import platform
-import errno
 
 import requests
 
diff --git a/kerncraft/intervals.py b/kerncraft/intervals.py
index f1e6a3e..a2f77ee 100755
--- a/kerncraft/intervals.py
+++ b/kerncraft/intervals.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """A simple interval implementation."""
 
 
diff --git a/kerncraft/kerncraft.py b/kerncraft/kerncraft.py
index d65d49c..f17fb4f 100755
--- a/kerncraft/kerncraft.py
+++ b/kerncraft/kerncraft.py
@@ -1,16 +1,7 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Comand line interface of Kerncraft."""
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
 # Version check
 import sys
-if sys.version_info[0] == 2 and sys.version_info < (2, 7) or \
-        sys.version_info[0] == 3 and sys.version_info < (3, 4):
-    print("Must use python 2.7 or 3.4 and greater.", file=sys.stderr)
-    sys.exit(1)
 import argparse
 import os.path
 import pickle
@@ -20,8 +11,6 @@
 import itertools
 
 from .pycparser import clean_code
-import six
-from six.moves import range
 from ruamel import yaml
 
 from . import models
@@ -34,7 +23,7 @@ def space(start, stop, num, endpoint=True, log=False, base=10):
     """
     Return list of evenly spaced integers over an interval.
 
-    Numbers can either be evenlty distributed in a linear space (if *log* is False) or in a log
+    Numbers can either be evenly distributed in a linear space (if *log* is False) or in a log
     space (if *log* is True). If *log* is True, base is used to define the log space basis.
 
     If *endpoint* is True, *stop* will be the last retruned value, as long as *num* >= 2.
@@ -48,16 +37,16 @@ def space(start, stop, num, endpoint=True, log=False, base=10):
         stop = math.log(stop, base)
 
     if endpoint:
-        steplength = float((stop-start))/float(num-1)
+        step_length = float((stop - start)) / float(num - 1)
     else:
-        steplength = float((stop-start))/float(num)
+        step_length = float((stop - start)) / float(num)
 
     i = 0
     while i < num:
         if log:
-            yield int(round(base**(start + i*steplength)))
+            yield int(round(base ** (start + i * step_length)))
         else:
-            yield int(round(start + i*steplength))
+            yield int(round(start + i * step_length))
         i += 1
 
 
@@ -73,11 +62,11 @@ class AppendStringRange(argparse.Action):
     """
     Argparse Action to append integer range from string.
 
-    A range discription must have the following format: start[-stop[:num[log[base]]]]
+    A range description must have the following format: start[-stop[:num[log[base]]]]
     if stop is given, a list of integers is compiled
-    if num is given, an evently spaced lsit of intergers from start to stop is compiled
+    if num is given, an evenly spaced list of integers from start to stop is compiled
     if log is given, the integers are evenly spaced on a log space
-    if base is given, the integers are evently spaced on that base (default: 10)
+    if base is given, the integers are evenly spaced on that base (default: 10)
     """
 
     def __call__(self, parser, namespace, values, option_string=None):
@@ -94,7 +83,7 @@ def __call__(self, parser, namespace, values, option_string=None):
                 if gd['stop'] is None:
                     values[1] = [int(gd['start'])]
                 elif gd['num'] is None:
-                    values[1] = list(range(int(gd['start']), int(gd['stop'])+1))
+                    values[1] = list(range(int(gd['start']), int(gd['stop']) + 1))
                 else:
                     log = gd['log'] is not None
                     base = int(gd['base']) if gd['base'] is not None else 10
@@ -116,7 +105,7 @@ def create_parser():
     """Return argparse parser."""
     parser = argparse.ArgumentParser(
         description='Analytical performance modelling and benchmarking toolkit.',
-        epilog='For help, examples, documenataion and bug reports go to:\nhttps://github.com'
+        epilog='For help, examples, documentation and bug reports go to:\nhttps://github.com'
                '/RRZE-HPC/kerncraft\nLicense: AGPLv3')
     parser.add_argument('--version', action='version', version='%(prog)s {}'.format(__version__))
     parser.add_argument('--machine', '-m', type=argparse.FileType('r'), required=True,
@@ -163,7 +152,7 @@ def create_parser():
                              'description file (-std=c99 is always added).')
 
     for m in models.__all__:
-        ag = parser.add_argument_group('arguments for '+m+' model', getattr(models, m).name)
+        ag = parser.add_argument_group('arguments for ' + m + ' model', getattr(models, m).name)
         getattr(models, m).configure_arggroup(ag)
 
     return parser
@@ -196,11 +185,11 @@ def run(parser, args, output_file=sys.stdout):
 
     # process kernel
     if not args.kernel_description:
-        code = six.text_type(args.code_file.read())
+        code = str(args.code_file.read())
         code = clean_code(code)
         kernel = KernelCode(code, filename=args.code_file.name, machine=machine)
     else:
-        description = six.text_type(args.code_file.read())
+        description = str(args.code_file.read())
         kernel = KernelDescription(yaml.load(description, Loader=yaml.Loader), machine=machine)
     # if no defines were given, guess suitable defines in-mem
     # TODO support in-cache
@@ -241,11 +230,11 @@ def run(parser, args, output_file=sys.stdout):
 
         for model_name in set(args.pmodel):
             # print header
-            print('{:=^80}'.format(' kerncraft '), file=output_file)
-            print('{:<40}{:>40}'.format(args.code_file.name, '-m '+args.machine.name),
+            print('{:^80}'.format(' kerncraft '), file=output_file)
+            print('{:<40}{:>40}'.format(args.code_file.name, '-m ' + args.machine.name),
                   file=output_file)
             print(' '.join(['-D {} {}'.format(k, v) for k, v in define]), file=output_file)
-            print('{:-^80}'.format(' '+model_name+' '), file=output_file)
+            print('{:-^80}'.format(' ' + model_name + ' '), file=output_file)
 
             if args.verbose > 1:
                 if not args.kernel_description:
@@ -274,10 +263,10 @@ def run(parser, args, output_file=sys.stdout):
 
         # Save storage to file (if requested)
         if args.store:
-            tempname = args.store.name + '.tmp'
-            with open(tempname, 'wb+') as f:
+            temp_name = args.store.name + '.tmp'
+            with open(temp_name, 'wb+') as f:
                 pickle.dump(result_storage, f)
-            shutil.move(tempname, args.store.name)
+            shutil.move(temp_name, args.store.name)
 
 
 def main():
diff --git a/kerncraft/kernel.py b/kerncraft/kernel.py
index 1c21a90..3e082e3 100755
--- a/kerncraft/kernel.py
+++ b/kerncraft/kernel.py
@@ -1,11 +1,5 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Representation of computational kernel for performance model analysis and helper functions."""
-
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
 from copy import deepcopy
 import operator
 import tempfile
@@ -19,16 +13,12 @@
 import string
 from itertools import chain
 from collections import defaultdict
+from itertools import zip_longest, lru_cache
 
 import sympy
 from sympy.utilities.lambdify import implemented_function
 from sympy.parsing.sympy_parser import parse_expr
 import numpy
-from six.moves import filter
-from six.moves import map
-from six.moves import zip_longest
-import six
-from pylru import lrudecorator
 
 from .pycparser import CParser, c_ast, plyparser
 from .pycparser.c_generator import CGenerator
@@ -186,7 +176,7 @@ def set_constant(self, name, value):
         :param name: may be a str or a sympy.Symbol
         :param value: must be an int
         """
-        assert isinstance(name, six.string_types) or isinstance(name, sympy.Symbol), \
+        assert isinstance(name, str) or isinstance(name, sympy.Symbol), \
             "constant name needs to be of type str, unicode or a sympy.Symbol"
         assert type(value) is int, "constant value needs to be of type int"
         if isinstance(name, sympy.Symbol):
@@ -214,7 +204,7 @@ def clear_state(self):
         self.constants = {}
         self.subs_consts.clear()  # clear LRU cache of function
 
-    @lrudecorator(40)
+    @lru_cache(40)
     def subs_consts(self, expr):
         """Substitute constants in expression unless it is already a number."""
         if isinstance(expr, numbers.Number):
@@ -711,7 +701,7 @@ def _get_basename(cls, aref):
         """
         if isinstance(aref.name, c_ast.ArrayRef):
             return cls._get_basename(aref.name)
-        elif isinstance(aref.name, six.string_types):
+        elif isinstance(aref.name, str):
             return aref.name
         else:
             return aref.name.name
diff --git a/kerncraft/likwid_bench_auto.py b/kerncraft/likwid_bench_auto.py
index 06940fe..f171ac0 100755
--- a/kerncraft/likwid_bench_auto.py
+++ b/kerncraft/likwid_bench_auto.py
@@ -1,16 +1,5 @@
-#!/usr/bin/env python
-from __future__ import print_function
-from __future__ import absolute_import
-from __future__ import unicode_literals
-from __future__ import division
-
-# Version check
+#!/usr/bin/env python3
 import sys
-if sys.version_info[0] == 2 and sys.version_info < (2, 6) or \
-        sys.version_info[0] == 3 and sys.version_info < (3, 4):
-    print("Must use python 2.6 or 3.4 and greater.", file=sys.stderr)
-    sys.exit(1)
-
 import subprocess
 import re
 from copy import copy
@@ -19,7 +8,6 @@
 from ruamel import yaml
 
 from .prefixedunit import PrefixedUnit
-from six.moves import range
 
 
 def get_match_or_break(regex, haystack, flags=re.MULTILINE):
diff --git a/kerncraft/machinemodel.py b/kerncraft/machinemodel.py
index 6a7ca0f..fe99eca 100755
--- a/kerncraft/machinemodel.py
+++ b/kerncraft/machinemodel.py
@@ -1,9 +1,5 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Machine model and helper functions."""
-
-from __future__ import absolute_import
-from __future__ import division
-
 from distutils.spawn import find_executable
 import re
 import sys
diff --git a/kerncraft/models/benchmark.py b/kerncraft/models/benchmark.py
index 6fc9403..00f0089 100644
--- a/kerncraft/models/benchmark.py
+++ b/kerncraft/models/benchmark.py
@@ -1,9 +1,5 @@
+#!/usr/bin/env python3
 """Benchmark model and helper functions."""
-from __future__ import print_function
-from __future__ import division
-from __future__ import unicode_literals
-from __future__ import absolute_import
-
 import subprocess
 from functools import reduce
 import operator
@@ -12,16 +8,8 @@
 import re
 from collections import defaultdict
 import string
-try:
-    # Python 3
-    from itertools import zip_longest
-except ImportError:
-    from itertools import izip_longest as zip_longest
 from pprint import pprint
 
-import six
-import sympy
-
 from kerncraft.prefixedunit import PrefixedUnit
 
 
@@ -276,7 +264,7 @@ def analyze(self):
         element_size = self.kernel.datatypes_size[self.kernel.datatype]
 
         # Build arguments to pass to command:
-        args = [bench] + [six.text_type(s) for s in list(self.kernel.constants.values())]
+        args = [bench] + [str(s) for s in list(self.kernel.constants.values())]
 
         # Determine base runtime with 100 iterations
         runtime = 0.0
@@ -289,7 +277,7 @@ def analyze(self):
             else:
                 repetitions *= 10
 
-            mem_results = self.perfctr(args+[six.text_type(repetitions)], group="MEM")
+            mem_results = self.perfctr(args+[str(repetitions)], group="MEM")
             runtime = mem_results['Runtime (RDTSC) [s]']
             time_per_repetition = runtime/float(repetitions)
         raw_results = [mem_results]
@@ -315,7 +303,7 @@ def analyze(self):
             measured_ctrs = {}
             for run in minimal_runs:
                 ctrs = ','.join([eventstr(e) for e in run])
-                r = self.perfctr(args+[six.text_type(repetitions)], group=ctrs)
+                r = self.perfctr(args+[str(repetitions)], group=ctrs)
                 raw_results.append(r)
                 measured_ctrs.update(r)
             # Match measured counters to symbols
diff --git a/kerncraft/models/ecm.py b/kerncraft/models/ecm.py
index 1174187..c80d143 100755
--- a/kerncraft/models/ecm.py
+++ b/kerncraft/models/ecm.py
@@ -1,17 +1,10 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Execution-Cache-Memory model class and helper functions."""
-
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
 import copy
 import sys
 import math
 from pprint import pformat
 
-import six
 try:
     import matplotlib
     matplotlib.use('Agg')
@@ -346,8 +339,8 @@ def report(self, output_file=sys.stdout):
             print('', file=output_file)
 
         if self.verbose > 1:
-            print('Ports and cycles:', six.text_type(self.results['port cycles']), file=output_file)
-            print('Uops:', six.text_type(self.results['uops']), file=output_file)
+            print('Ports and cycles:', str(self.results['port cycles']), file=output_file)
+            print('Uops:', str(self.results['uops']), file=output_file)
 
             print('Throughput: {}'.format(
                       self.conv_cy(self.results['cl throughput'], self._args.unit)),
diff --git a/kerncraft/models/layer_condition.py b/kerncraft/models/layer_condition.py
index abf1d54..85ea5f0 100755
--- a/kerncraft/models/layer_condition.py
+++ b/kerncraft/models/layer_condition.py
@@ -1,45 +1,14 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Layer condition model and helper functions"""
-
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
 import sys
 from itertools import chain
 from pprint import pprint
 from collections import defaultdict
+from functools import cmp_to_key
 
 import sympy
 
 
-# Not useing functools.cmp_to_key, because it does not exit in python 2.x
-def cmp_to_key(mycmp):
-    """Convert a cmp= function into a key= function"""
-    class K(object):
-        def __init__(self, obj, *args):
-            self.obj = obj
-
-        def __lt__(self, other):
-            return mycmp(self.obj, other.obj) < 0
-
-        def __gt__(self, other):
-            return mycmp(self.obj, other.obj) > 0
-
-        def __eq__(self, other):
-            return mycmp(self.obj, other.obj) == 0
-
-        def __le__(self, other):
-            return mycmp(self.obj, other.obj) <= 0
-
-        def __ge__(self, other):
-            return mycmp(self.obj, other.obj) >= 0
-
-        def __ne__(self, other):
-            return mycmp(self.obj, other.obj) != 0
-
-
 class LC(object):
     """
     Representation of the layer condition model.
diff --git a/kerncraft/models/roofline.py b/kerncraft/models/roofline.py
index 6b24fec..825e0cd 100755
--- a/kerncraft/models/roofline.py
+++ b/kerncraft/models/roofline.py
@@ -1,10 +1,5 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Roofline model and helper functions."""
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
 import sys
 from pprint import pformat  # Do not use pprint, breaks in combination with --store and StringIO
 
diff --git a/kerncraft/picklemerge.py b/kerncraft/picklemerge.py
index 112b2a4..e2bf290 100755
--- a/kerncraft/picklemerge.py
+++ b/kerncraft/picklemerge.py
@@ -1,9 +1,5 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Merge two pickle files containing dictionarys recursively."""
-
-from __future__ import print_function
-from __future__ import absolute_import
-
 import argparse
 import pickle
 import collections
diff --git a/kerncraft/prefixedunit.py b/kerncraft/prefixedunit.py
index 279f30d..73cc490 100755
--- a/kerncraft/prefixedunit.py
+++ b/kerncraft/prefixedunit.py
@@ -1,12 +1,7 @@
-#!/usr/bin/env python
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
+#!/usr/bin/env python3
+import re
 
 from ruamel import yaml
-import re
-import six
 
 
 class PrefixedUnit(yaml.YAMLObject):
@@ -26,11 +21,11 @@ def from_yaml(cls, loader, node):
 
     @classmethod
     def to_yaml(cls, dumper, data):
-        return dumper.represent_scalar(cls.yaml_tag, six.text_type(data))
+        return dumper.represent_scalar(cls.yaml_tag, str(data))
 
     def __init__(self, *args):
         if len(args) == 1:
-            if isinstance(args[0], six.string_types):
+            if isinstance(args[0], str):
                 m = re.match(
                     r'^(?P<value>(?:[0-9]+(?:\.[0-9]+)?|inf)) (?P<prefix>[kMGTP])?(?P<unit>.*)$',
                     args[0])
diff --git a/kerncraft/roofline-plot.py b/kerncraft/roofline-plot.py
index 56db8ad..70f4afb 100755
--- a/kerncraft/roofline-plot.py
+++ b/kerncraft/roofline-plot.py
@@ -1,15 +1,10 @@
-#!/usr/bin/env python
-
-from __future__ import absolute_import
-
+#!/usr/bin/env python3
 from pprint import pprint
 
-# matplotlib.use('Agg')
 import matplotlib.pyplot as plt
 from ruamel import yaml
 
 from .prefixedunit import PrefixedUnit
-from six.moves import range
 
 
 def frange(start, stop, step=1.0):
diff --git a/likwid-counter-packing.py b/likwid-counter-packing.py
index 5d77ba5..f0ec1e8 100755
--- a/likwid-counter-packing.py
+++ b/likwid-counter-packing.py
@@ -1,12 +1,7 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 from pprint import pprint
 import re
 import string
-try:
-    # Python 3
-    from itertools import zip_longest
-except ImportError:
-    from itertools import izip_longest as zip_longest
 
 
 def group_iterator(group):
diff --git a/setup.py b/setup.py
index afe8c58..adeca9f 100755
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,4 @@
-#!/usr/bin/env python
-from __future__ import absolute_import
-
+#!/usr/bin/env python3
 # Always prefer setuptools over distutils
 from setuptools import setup, find_packages
 from setuptools.command.build_py import build_py as _build_py
@@ -107,8 +105,6 @@ def make_release_tree(self, base_dir, files):
 
         # Specify the Python versions you support here. In particular, ensure
         # that you indicate whether you support Python 2, Python 3 or both.
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.4',
     ],
@@ -129,7 +125,6 @@ def make_release_tree(self, base_dir, files):
     # https://packaging.python.org/en/latest/requirements.html
     install_requires=[
         'ruamel.yaml>=0.13.4,<0.14.0',
-        'six',
         'sympy>=0.7.7',
         'pycachesim>=0.1.5',
         'pylru',
diff --git a/tests/all_tests.py b/tests/all_tests.py
index 20544c7..995cdfe 100755
--- a/tests/all_tests.py
+++ b/tests/all_tests.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import unittest
 import sys
 
diff --git a/tests/test_files/dummy_likwid/likwid-bench b/tests/test_files/dummy_likwid/likwid-bench
index b7e77f7..8e1ef54 100755
--- a/tests/test_files/dummy_likwid/likwid-bench
+++ b/tests/test_files/dummy_likwid/likwid-bench
@@ -1,6 +1,4 @@
-#!/usr/bin/env python
-from __future__ import print_function
-
+#!/usr/bin/env python3
 import sys
 import re
 
diff --git a/tests/test_files/dummy_likwid/likwid-perfctr b/tests/test_files/dummy_likwid/likwid-perfctr
index 22aaed3..e7bcdf3 100755
--- a/tests/test_files/dummy_likwid/likwid-perfctr
+++ b/tests/test_files/dummy_likwid/likwid-perfctr
@@ -1,6 +1,4 @@
-#!/usr/bin/env python
-from __future__ import print_function
-
+#!/usr/bin/env python3
 import sys
 import re
 
diff --git a/tests/test_files/dummy_likwid/likwid-topology b/tests/test_files/dummy_likwid/likwid-topology
index c44da4c..1691b6d 100755
--- a/tests/test_files/dummy_likwid/likwid-topology
+++ b/tests/test_files/dummy_likwid/likwid-topology
@@ -1,6 +1,4 @@
-#!/usr/bin/env python
-from __future__ import print_function
-
+#!/usr/bin/env python3
 import sys
 import re
 
diff --git a/tests/test_intervals.py b/tests/test_intervals.py
index f9d013f..d0c36c0 100644
--- a/tests/test_intervals.py
+++ b/tests/test_intervals.py
@@ -1,9 +1,7 @@
+#!/usr/bin/env python3
 """
 Unit tests for intervals module
 """
-from __future__ import print_function
-
-import sys
 import unittest
 
 from kerncraft.intervals import Intervals
diff --git a/tests/test_kerncraft.py b/tests/test_kerncraft.py
index 53a9032..c2490d9 100644
--- a/tests/test_kerncraft.py
+++ b/tests/test_kerncraft.py
@@ -1,23 +1,16 @@
+#!/usr/bin/env python3
 """
 High-level tests for the overall functionallity and things in kc.py
 """
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
-import sys
 import os
 import unittest
 import tempfile
 import shutil
 import pickle
-from pprint import pprint
 from io import StringIO
 from distutils.spawn import find_executable
 import platform
 
-import six
 import sympy
 
 from kerncraft import kerncraft as kc
@@ -61,7 +54,7 @@ def test_2d5pt_ECMData_SIM(self):
         self.assertEqual(list(results), ['2d-5pt.c'])
 
         # Check for correct variations of constants
-        six.assertCountEqual(self,
+        self.assertCountEqual(
             [sorted(map(str, r)) for r in results['2d-5pt.c']],
             [sorted(map(str, r)) for r in [
                 ((sympy.var('M'), 50), (sympy.var('N'), 1000)), ((sympy.var('M'), 50),
@@ -71,7 +64,7 @@ def test_2d5pt_ECMData_SIM(self):
         result = results['2d-5pt.c'][[k for k in results['2d-5pt.c']
                                       if (sympy.var('N'), 1000) in k][0]]
 
-        six.assertCountEqual(self, result, ['ECMData'])
+        self.assertCountEqual(result, ['ECMData'])
 
         ecmd = result['ECMData']
         # 2 arrays * 1000*50 doubles/array * 8 Bytes/double = 781kB
@@ -104,7 +97,7 @@ def test_2d5pt_ECMData_LC(self):
         self.assertEqual(list(results), ['2d-5pt.c'])
 
         # Check for correct variations of constants
-        six.assertCountEqual(self,
+        self.assertCountEqual(
             [sorted(map(str, r)) for r in results['2d-5pt.c']],
             [sorted(map(str, r)) for r in [
                 ((sympy.var('M'), 50), (sympy.var('N'), 1000)), ((sympy.var('M'), 50),
@@ -113,7 +106,7 @@ def test_2d5pt_ECMData_LC(self):
         # Output of first result:
         result = results['2d-5pt.c'][[k for k in results['2d-5pt.c'] if (sympy.var('N'), 1000) in k][0]]
 
-        six.assertCountEqual(self, result, ['ECMData'])
+        self.assertCountEqual(result, ['ECMData'])
 
         ecmd = result['ECMData']
         # 2 arrays * 1000*50 doubles/array * 8 Bytes/double = 781kB
@@ -143,7 +136,7 @@ def test_2d5pt_Roofline(self):
         self.assertEqual(list(results), ['2d-5pt.c'])
 
         # Check for correct variations of constants
-        six.assertCountEqual(self,
+        self.assertCountEqual(
             [sorted(map(str, r)) for r in results['2d-5pt.c']],
             [sorted(map(str, r)) for r in [
                 ((sympy.var('M'), 50), (sympy.var('N'), 1024)), ((sympy.var('M'), 50), (sympy.var('N'), 2048)), ((sympy.var('M'), 50), (sympy.var('N'), 4096))]])
@@ -151,7 +144,7 @@ def test_2d5pt_Roofline(self):
         # Output of first result:
         result = results['2d-5pt.c'][[k for k in results['2d-5pt.c'] if (sympy.var('N'), 4096) in k][0]]
 
-        six.assertCountEqual(self, result, ['Roofline'])
+        self.assertCountEqual(result, ['Roofline'])
 
         roofline = result['Roofline']
         self.assertAlmostEqual(roofline['min performance'], 5802500000.0, places=0)
@@ -285,14 +278,14 @@ def test_2d5pt_ECMCPU(self):
         self.assertEqual(list(results), ['2d-5pt.c'])
 
         # Check for correct variations of constants
-        six.assertCountEqual(self,
+        self.assertCountEqual(
             [sorted(map(str, r)) for r in results['2d-5pt.c']],
             [sorted(map(str, r)) for r in [((sympy.var('M'), 1000), (sympy.var('N'), 2000))]])
 
         # Output of first result:
         result = list(results['2d-5pt.c'].values())[0]
 
-        six.assertCountEqual(self, result, ['ECMCPU'])
+        self.assertCountEqual(result, ['ECMCPU'])
 
         ecmd = result['ECMCPU']
         self.assertAlmostEqual(ecmd['T_OL'], 12, places=1)
@@ -322,14 +315,14 @@ def test_2d5pt_ECM(self):
         self.assertEqual(list(results), ['2d-5pt.c'])
 
         # Check for correct variations of constants
-        six.assertCountEqual(self,
+        self.assertCountEqual(
             [sorted(map(str, r)) for r in results['2d-5pt.c']],
             [sorted(map(str, r)) for r in [((sympy.var('M'), 1000), (sympy.var('N'), 2000))]])
 
         # Output of first result:
         result = list(results['2d-5pt.c'].values())[0]
 
-        six.assertCountEqual(self, result, ['ECM'])
+        self.assertCountEqual(result, ['ECM'])
 
         ecmd = result['ECM']
         # 2 * 2000*1000 * 8 = 31MB
@@ -367,14 +360,14 @@ def test_2d5pt_RooflineIACA(self):
         self.assertEqual(list(results), ['2d-5pt.c'])
 
         # Check for correct variations of constants
-        six.assertCountEqual(self,
+        self.assertCountEqual(
             [sorted(map(str, r)) for r in results['2d-5pt.c']],
             [sorted(map(str, r)) for r in [((sympy.var('M'), 1000), (sympy.var('N'), 4000))]])
 
         # Output of first result:
         result = list(results['2d-5pt.c'].values())[0]
 
-        six.assertCountEqual(self, result, ['RooflineIACA'])
+        self.assertCountEqual(result, ['RooflineIACA'])
 
         roofline = result['RooflineIACA']
         self.assertAlmostEqual(roofline['min performance'], 2900000000.0, places=0)
@@ -414,14 +407,14 @@ def test_2d5pt_Benchmark(self):
         self.assertEqual(list(results), ['2d-5pt.c'])
 
         # Check for correct variations of constants
-        six.assertCountEqual(self,
+        self.assertCountEqual(
             [sorted(map(str, r)) for r in results['2d-5pt.c']],
             [sorted(map(str, r)) for r in [((sympy.var('M'), 1000), (sympy.var('N'), 1000))]])
 
         # Output of first result:
         result = list(results['2d-5pt.c'].values())[0]
 
-        six.assertCountEqual(self, result, ['Benchmark'])
+        self.assertCountEqual(result, ['Benchmark'])
 
         roofline = result['Benchmark']
         correct_results = {
diff --git a/tests/test_kernel.py b/tests/test_kernel.py
index 9ad81a9..9241ce3 100644
--- a/tests/test_kernel.py
+++ b/tests/test_kernel.py
@@ -1,26 +1,13 @@
+#!/usr/bin/env python3
 """
 High-level tests for the overall functionallity and things in kc.py
 """
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
-import sys
 import os
 import unittest
-import tempfile
-import shutil
-import pickle
-from pprint import pprint
-from io import StringIO
-from itertools import chain
 
-import six
-import sympy
 from ruamel import yaml
 
-from kerncraft.kernel import Kernel, KernelCode, KernelDescription
+from kerncraft.kernel import KernelCode, KernelDescription
 
 
 class TestKernel(unittest.TestCase):
@@ -111,6 +98,5 @@ def test_from_description(self):
         self.assertEqual(k_descr._loop_stack, k_code._loop_stack)
 
 if __name__ == '__main__':
-    #unittest.main()
     suite = unittest.TestLoader().loadTestsFromTestCase(TestKernel)
     unittest.TextTestRunner(verbosity=2).run(suite)
diff --git a/tests/test_layer_condition.py b/tests/test_layer_condition.py
index fd1107b..e6a9b64 100644
--- a/tests/test_layer_condition.py
+++ b/tests/test_layer_condition.py
@@ -1,23 +1,14 @@
+#!/usr/bin/env python3
 """
 High-level tests for the overall functionallity and things in kc.py
 """
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
-import sys
 import os
 import unittest
 import tempfile
 import shutil
 import pickle
-from pprint import pprint
 from io import StringIO
-from distutils.spawn import find_executable
-import platform
 
-import six
 import sympy
 
 from kerncraft import kerncraft as kc
diff --git a/tests/test_likwid_bench_auto.py b/tests/test_likwid_bench_auto.py
index b965003..496a2f1 100644
--- a/tests/test_likwid_bench_auto.py
+++ b/tests/test_likwid_bench_auto.py
@@ -1,24 +1,9 @@
+#!/usr/bin/env python3
 """
 High-level tests for the overall functionallity and things in kc.py
 """
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-
-import sys
 import os
 import unittest
-import tempfile
-import shutil
-import pickle
-from pprint import pprint
-from io import StringIO
-from distutils.spawn import find_executable
-import platform
-
-import six
-import sympy
 
 from kerncraft import likwid_bench_auto as lba
 from kerncraft.prefixedunit import PrefixedUnit
diff --git a/tox.ini b/tox.ini
index 210dc69..e0af49e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py34,py35,py36
+envlist = py34,py35,py36
 
 [testenv]
 install_command = pip install {opts} {packages}