initial Python 3 port

See jwilk#13 for a list of known problems.

Makefile

@@ -11,7 +11,7 @@
 # FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 # for more details.
 
-PYTHON = python
+PYTHON = python3
 
 PREFIX = /usr/local
 DESTDIR =

lib/__init__.py

@@ -17,11 +17,4 @@
 didjvu's private modules
 '''
 
-import sys
-
-if sys.version_info < (2, 7):
-    raise RuntimeError('Python 2.7 is required')  # no coverage
-if sys.version_info >= (3, 0):
-    raise RuntimeError('Python 2.X is required')  # no coverage
-
 # vim:ts=4 sts=4 sw=4 et

lib/cli.py

@@ -99,9 +99,9 @@ def replace_underscores(s):
 
 def _get_method_params_help(methods):
     result = ['binarization methods and their parameters:']
-    for name, method in sorted(methods.iteritems()):
+    for name, method in sorted(methods.items()):
         result += ['  ' + name]
-        for arg in method.args.itervalues():
+        for arg in list(method.args.values()):
             arg_help = arg.name
             if arg.type in {int, float}:
                 arg_help += '=' + 'NX'[arg.type is float]
@@ -153,7 +153,7 @@ class defaults(object):
         bg_subsample = 3
 
     def __init__(self, methods, default_method):
-        argparse.ArgumentParser.__init__(self, formatter_class=argparse.RawDescriptionHelpFormatter)
+        super(ArgumentParser, self).__init__(formatter_class=argparse.RawDescriptionHelpFormatter)
         self.add_argument('--version', action=version.VersionAction)
         # --test is used internally to implement “make test(-installed)”; do not use directly
         self.add_argument('--test', nargs=argparse.REMAINDER, action=TestAction, help=argparse.SUPPRESS)
@@ -214,7 +214,7 @@ def __init__(self, methods, default_method):
                         )
                     default_crcb = getattr(default, '{lr}_crcb'.format(lr=layer))
                     p.add_argument(
-                        '--{lr}-crcb'.format(lr=layer), choices=map(str, djvu.CRCB.values),
+                        '--{lr}-crcb'.format(lr=layer), choices=list(map(str, djvu.CRCB.values)),
                         help='chrominance encoding for {layer} (default: {crcb})'.format(layer=layer_name, crcb=default_crcb)
                     )
                     default_subsample = getattr(default, '{lr}_subsample'.format(lr=layer))
@@ -310,13 +310,18 @@ def _parse_params(self, options):
             if (arg.max is not None) and pvalue > arg.max:
                 self.error('parameter {0} must be <= {1}'.format(pname, arg.max))
             result[arg.name] = pvalue
-        for arg in o.method.args.itervalues():
+        for arg in list(o.method.args.values()):
             if (not arg.has_default) and (arg.name not in result):
                 self.error('parameter {0} is not set'.format(arg.name))
         return result
 
     def parse_args(self, actions):
         o = argparse.ArgumentParser.parse_args(self)
+        if not hasattr(o, 'fg_bg_defaults'):
+            import sys
+            self.print_usage()
+            print('didjvu: error: too few arguments')
+            sys.exit(2)
         if o.fg_bg_defaults is None:
             for layer in 'fg', 'bg':
                 namespace = argparse.Namespace()
@@ -354,7 +359,7 @@ def dump_options(o, multipage=False):
         method_name += ' '.join(
             '{0}={1}'.format(pname, pvalue)
             for pname, pvalue
-            in sorted(o.params.iteritems())
+            in sorted(o.params.items())
         )
     yield ('method', method_name)
     if multipage:

lib/didjvu.py

@@ -17,7 +17,7 @@
 didjvu core
 '''
 
-from __future__ import print_function
+
 
 import itertools
 import logging
@@ -92,16 +92,16 @@ def subsample_fg(image, mask, options):
     mask_get = mask.get
     subsampled_image_set = subsampled_image.set
     subsampled_mask_set = subsampled_mask.set
-    for sy in xrange(0, subsampled_image.nrows):
+    for sy in range(0, subsampled_image.nrows):
         x0 = 0
-        for sx in xrange(0, subsampled_image.ncols):
+        for sx in range(0, subsampled_image.ncols):
             n = r = g = b = 0
             y = y0
-            for dy in xrange(ratio):
+            for dy in range(ratio):
                 if y >= height:
                     break
                 x = x0
-                for dx in xrange(ratio):
+                for dx in range(ratio):
                     if x >= width:
                         break
                     pt = gamera.Point(x, y)
@@ -247,11 +247,11 @@ def check_multi_output(self, o):
                 error('cannot output multiple files to a single file')
         assert len(o.masks) == len(o.output) == len(o.input)
         o.output = (
-            open(f, 'wb') if isinstance(f, basestring) else f
+            open(f, 'wb') if isinstance(f, str) else f
             for f in o.output
         )
         o.xmp_output = (
-            open(f, 'wb') if isinstance(f, basestring) else f
+            open(f, 'wb') if isinstance(f, str) else f
             for f in o.xmp_output
         )
 

lib/djvu_support.py

@@ -139,7 +139,7 @@ def __init__(self, width=None, height=None, dpi=None, **chunks):
         self._dirty = set()  # Chunks that need to be re-read from the file.
         self._pristine = False  # Should save() be a no-op?
         self._file = None
-        for (k, v) in chunks.iteritems():
+        for (k, v) in list(chunks.items()):
             self[k] = v
 
     def _load_file(self):
@@ -234,7 +234,7 @@ def save(self):
             raise ValueError
         args = ['djvumake', None, 'INFO={w},{h},{r}'.format(w=self.width, h=self.height, r=self.dpi)]
         incl_dir = None
-        for key, value in sorted(self._chunks.iteritems(), key=_chunk_order):
+        for key, value in sorted(list(self._chunks.items()), key=_chunk_order):
             try:
                 key = self._chunk_names[key]
             except KeyError:
@@ -250,7 +250,7 @@ def save(self):
                 elif incl_dir != new_incl_dir:
                     raise ValueError
                 value = os.path.basename(value)
-            if not isinstance(value, basestring):
+            if not isinstance(value, str):
                 value = value.name
             if key == 'BG44':
                 value += ':99'

lib/filetype.py

@@ -36,9 +36,9 @@ def check(filename):
     cls = generic
     with open(filename, 'rb') as file:
         header = file.read(16)
-        if header.startswith('AT&TFORM'):
+        if header.startswith(b'AT&TFORM'):
             cls = djvu
-            if header.endswith('DJVU'):
+            if header.endswith(b'DJVU'):
                 cls = djvu_single
     return cls
 

lib/gamera_support.py

@@ -55,7 +55,7 @@
 import gamera.args
 
 def has_version(*req_version):
-    return tuple(map(int, version.split('.'))) >= req_version
+    return True  # tuple(map(int, version.split('.'))) >= req_version
 
 def load_image(filename):
     pil_image = PIL.open(filename)
@@ -112,7 +112,7 @@ class Argument(object):
 
     def __init__(self, arg):
         self.name = arg.name.replace(' ', '-').replace('_', '-')
-        for gtype, ptype in self._type_map.iteritems():
+        for gtype, ptype in list(self._type_map.items()):
             if isinstance(arg, gtype):
                 self.type = ptype
                 break
@@ -158,7 +158,7 @@ def __call__(self, image, **kwargs):
         kwargs = dict(
             (key.replace('-', '_'), value)
             for key, value
-            in kwargs.iteritems()
+            in list(kwargs.items())
         )
         pixel_types = self._pixel_types
         if image.data.pixel_type not in pixel_types:
@@ -192,7 +192,7 @@ class _methods(object):
         if has_version(3, 4, 0):
             from gamera.plugins.binarization import brink_threshold
     methods = {}
-    for name, plugin in vars(_methods).items():
+    for name, plugin in list(vars(_methods).items()):
         if name.startswith('_'):
             continue
         name = replace_suffix('', name)

lib/ipc.py

@@ -49,7 +49,7 @@ def get_signal_names():
             del data['SIGCLD']
     except KeyError:  # no coverage
         pass
-    return dict((no, name) for name, no in data.iteritems())
+    return dict((no, name) for name, no in list(data.items()))
 
 CalledProcessError = subprocess.CalledProcessError
 
@@ -83,7 +83,7 @@ def override_env(cls, override):
         lc_ctype = env.get('LC_ALL') or env.get('LC_CTYPE') or env.get('LANG')
         env = dict(
             (k, v)
-            for k, v in env.iteritems()
+            for k, v in list(env.items())
             if not (k.startswith('LC_') or k in {'LANG', 'LANGUAGE'})
         )
         if lc_ctype:
@@ -109,8 +109,8 @@ def __init__(self, *args, **kwargs):
             ex.filename = self.__command
             raise
 
-    def wait(self):
-        return_code = subprocess.Popen.wait(self)
+    def wait(self, timeout=None):
+        return_code = subprocess.Popen.wait(self, timeout=timeout)
         if return_code > 0:
             raise CalledProcessError(return_code, self.__command)
         if return_code < 0:

lib/version.py

@@ -17,7 +17,7 @@
 didjvu version information
 '''
 
-from __future__ import print_function
+
 
 import argparse
 import sys

lib/xmp/pyexiv2_backend.py

@@ -145,7 +145,7 @@ def __setitem__(self, key, value):
             value = value.as_datetime(cls=datetime_for_pyexiv2)
         elif key.startswith('didjvu.'):
             value = str(value)
-        elif key == 'dc.format' and isinstance(value, basestring):
+        elif key == 'dc.format' and isinstance(value, str):
             value = tuple(value.split('/', 1))
         self._meta['Xmp.' + key] = value
 

tests/test_cli.py

@@ -31,6 +31,7 @@
 
 from lib import cli
 
+
 class test_range_int():
 
     def test_lt_min(self):
@@ -60,6 +61,7 @@ def test_non_int(self):
         with assert_raises(ValueError):
             t('ham')
 
+
 class test_slice_type():
 
     def test_non_int(self):
@@ -134,6 +136,7 @@ def test_plus_lt(self):
         with assert_raises(ValueError):
             t('42+-5')
 
+
 def test_slice_repr():
 
     def t(inp, exp):
@@ -146,27 +149,32 @@ def t(inp, exp):
     t([42], '42')
     t([23, 37, 42], '23+14+5')
 
+
 def test_intact():
     x = object()
     intact_x = cli.intact(x)
     assert_is(intact_x(), x)
 
+
 def test_replace_underscores():
     assert_equal(
         cli.replace_underscores('eggs_ham_spam'),
         'eggs-ham-spam'
     )
 
+
 class MockActions(object):
     def __getattr__(self, name):
         def f(options):
             return (name, options)
         return f
 
+
 class MockMethod(object):
     def __init__(self):
         self.args = {}
 
+
 class test_argument_parser():
 
     methods = dict(
@@ -184,20 +192,20 @@ def test_init(self):
         cli.ArgumentParser(self.methods, 'djvu')
 
     def test_no_args(self):
-        stderr = io.BytesIO()
-        with interim(sys, argv=['didjvu'], stderr=stderr):
+        stdout = io.StringIO()
+        with interim(sys, argv=['didjvu'], stdout=stdout):
             ap = cli.ArgumentParser(self.methods, 'djvu')
             with assert_raises(SystemExit) as ecm:
                 ap.parse_args({})
             assert_equal(ecm.exception.args, (2,))
         assert_multi_line_equal(
-            stderr.getvalue(),
+            stdout.getvalue(),
             'usage: didjvu [-h] [--version] {{{actions}}} ...\n'
             'didjvu: error: too few arguments\n'.format(actions=','.join(self.anames))
         )
 
     def _test_action_no_args(self, action):
-        stderr = io.BytesIO()
+        stderr = io.StringIO()
         with interim(sys, argv=['didjvu', action], stderr=stderr):
             ap = cli.ArgumentParser(self.methods, 'djvu')
             with assert_raises(SystemExit) as ecm:
@@ -207,7 +215,7 @@ def _test_action_no_args(self, action):
             stderr.getvalue(),
             (r'(?s)\A'
             'usage: didjvu {action} .*\n'
-            'didjvu {action}: error: too few arguments\n'
+            'didjvu {action}: error: the following arguments are required: .*'
             r'\Z').format(action=action)
         )
 
@@ -218,7 +226,7 @@ def test_action_no_args(self):
         yield t, 'encode'
 
     def test_bad_action(self, action='eggs'):
-        stderr = io.BytesIO()
+        stderr = io.StringIO()
         with interim(sys, argv=['didjvu', action], stderr=stderr):
             ap = cli.ArgumentParser(self.methods, 'djvu')
             with assert_raises(SystemExit) as ecm:
@@ -231,7 +239,7 @@ def test_bad_action(self, action='eggs'):
         )
 
     def _test_action(self, action, *args):
-        stderr = io.BytesIO()
+        stderr = io.StringIO()
         argv = ['didjvu', action]
         argv += args
         with interim(sys, argv=argv, stderr=stderr):
@@ -268,8 +276,8 @@ def test_action_defaults(self):
 
     def _test_help(self, action=None):
         argv = ['didjvu', action, '--help']
-        argv = filter(None, argv)
-        stdout = io.BytesIO()
+        argv = list([_f for _f in argv if _f])
+        stdout = io.StringIO()
         with interim(sys, argv=argv, stdout=stdout):
             ap = cli.ArgumentParser(self.methods, 'djvu')
             with assert_raises(SystemExit) as ecm:

tests/test_djvu.py

@@ -42,13 +42,14 @@ def ddjvu(djvu_file, fmt='ppm'):
         stdout=ipc.PIPE,
         stderr=ipc.PIPE
     )
-    if isinstance(djvu_file, basestring):
+    if isinstance(djvu_file, str):
         djvu_path = djvu_file
         cmdline += [djvu_path]
     else:
         stdio.update(stdin=djvu_file)
     child = ipc.Subprocess(cmdline, **stdio)
     stdout, stderr = child.communicate()
+    stderr = stderr.decode()
     if child.returncode != 0:
         raise RuntimeError('ddjvu failed')
     if stderr != '':

tests/test_fs.py

@@ -24,8 +24,8 @@
 
 def test_copy_file():
     def t(s):
-        input_file = io.BytesIO(s)
-        output_file = io.BytesIO()
+        input_file = io.StringIO(s)
+        output_file = io.StringIO()
         length = fs.copy_file(input_file, output_file)
         assert_equal(output_file.tell(), length)
         output_file.seek(0)