Python 2.6 tested on Windows. No subprocess32.

Using Popen and defining my own check_output() instead of installing
subprocess32 which doesn't work on Windows.

README.rst

@@ -6,7 +6,7 @@ This is just a simple flake8 plugin for the `pep257 <https://github.com/GreenSte
 validating docstrings.
 
 * Python 2.6, 2.7, PyPy, 3.3, 3.4, and 3.5 supported on Linux and OS X.
-* Python 2.7, 3.3, 3.4, and 3.5 supported on Windows (both 32 and 64 bit versions of Python).
+* Python 2.6, 2.7, 3.3, 3.4, and 3.5 supported on Windows (both 32 and 64 bit versions of Python).
 
 .. image:: https://img.shields.io/appveyor/ci/Robpol86/flake8-pep257/master.svg?style=flat-square&label=AppVeyor%20CI
     :target: https://ci.appveyor.com/project/Robpol86/flake8-pep257

appveyor.yml

@@ -5,4 +5,4 @@ artifacts:
 # Run.
 init: set PATH=C:\Python35-x64;C:\Python35-x64\Scripts;%PATH%
 build_script: pip install tox
-test_script: tox -e lint,py35,py34,py33,py27,py35x64,py34x64,py33x64,py27x64
+test_script: tox -e lint,py35,py34,py33,py27,py26,py35x64,py34x64,py33x64,py27x64,py26x64

tests/__init__.py

@@ -1,11 +1,37 @@
 """Non-fixture code shared among test modules."""
 
+import os
+import subprocess
 
-try:
-    from subprocess import check_output, STDOUT
-except ImportError:
-    from subprocess32 import check_output, STDOUT
 
+def check_output(command, cwd=None, env=None, stdin=None):
+    """Basically subprocess.check_output since it doesn't exist in Python 2.6.
 
-assert check_output
-assert STDOUT
+    :raise CalledProcessError: Command exits non-zero.
+
+    :param iter command: Command to run.
+    :param str cwd: Current working directory.
+    :param dict env: Set environment variables.
+    :param file stdin: Pipe handle to subprocess' stdin.
+
+    :return: Command output.
+    :rtype: str
+    """
+    stdout = subprocess.STDOUT
+    pipe = subprocess.PIPE
+
+    # Setup env.
+    environ = os.environ.copy()
+    if env:
+        environ.update(env)
+
+    # Run command.
+    with open(os.devnull) as null:
+        proc = subprocess.Popen(command, cwd=cwd, env=environ, stdout=pipe, stderr=stdout, stdin=stdin or null)
+        output = proc.communicate()[0].decode('utf-8')  # Blocks until command exits.
+
+    # Raise if non-zero exit.
+    if proc.poll() != 0:
+        raise subprocess.CalledProcessError(proc.poll(), command, output=output)
+
+    return output

tests/test_default.py

@@ -6,7 +6,7 @@
 import flake8.main
 import pytest
 
-from tests import check_output, STDOUT
+from tests import check_output
 
 EXPECTED = """\
 ./sample.py:1:1: D100 Missing docstring in public module
@@ -72,7 +72,7 @@ def test_subprocess(tmpdir, stdin):
     command = [find_executable('flake8'), '--exit-zero', '-' if stdin else '.']
     environ = os.environ.copy()
     environ['COV_CORE_DATAFILE'] = ''  # Disable pytest-cov's subprocess coverage feature. Doesn't work right now.
-    out = check_output(command, stderr=STDOUT, cwd=cwd, stdin=stdin_handle, env=environ).decode('utf-8')
+    out = check_output(command, cwd=cwd, stdin=stdin_handle, env=environ)
 
     # Clean.
     if stdin:

tests/test_explain.py

@@ -6,7 +6,7 @@
 import flake8.main
 import pytest
 
-from tests import check_output, STDOUT
+from tests import check_output
 
 EXPECTED = list()
 EXPECTED.append("""\
@@ -187,7 +187,7 @@ def test_subprocess(tmpdir, stdin, which_cfg):
     command = [find_executable('flake8'), '--exit-zero', '-' if stdin else '.']
     environ = os.environ.copy()
     environ['COV_CORE_DATAFILE'] = ''  # Disable pytest-cov's subprocess coverage feature. Doesn't work right now.
-    out = check_output(command, stderr=STDOUT, cwd=cwd, stdin=stdin_handle, env=environ).decode('utf-8')
+    out = check_output(command, cwd=cwd, stdin=stdin_handle, env=environ)
 
     # Clean.
     if stdin:

tests/test_ignore.py

@@ -6,7 +6,7 @@
 import flake8.main
 import pytest
 
-from tests import check_output, STDOUT
+from tests import check_output
 
 EXPECTED = """\
 ./sample.py:1:1: D100 Missing docstring in public module
@@ -86,7 +86,7 @@ def test_subprocess(tmpdir, ignore, stdin, which_cfg):
     command = [find_executable('flake8'), '--exit-zero', '-' if stdin else '.']
     environ = os.environ.copy()
     environ['COV_CORE_DATAFILE'] = ''  # Disable pytest-cov's subprocess coverage feature. Doesn't work right now.
-    out = check_output(command, stderr=STDOUT, cwd=cwd, stdin=stdin_handle, env=environ).decode('utf-8')
+    out = check_output(command, cwd=cwd, stdin=stdin_handle, env=environ)
 
     # Clean.
     if stdin:

tox.ini

@@ -14,7 +14,6 @@ commands =
 deps =
     flake8==2.5.4
     pytest-cov==2.2.1
-    py26: subprocess32==3.2.7
 usedevelop = True
 
 [testenv:py35x64]