fix #834: avoid warnings in Python 3.8

gdementen · gdementen · commit e3fd35f6d2f3 · 2019-12-16T08:59:46.000+01:00
* use == to compare to a string literal instead of "is"
* reworked sequence() to avoid comparing mult to 1 using "is"
* moved compatibility layer with python2.7 to a specific compat module and import abstract base classes from there
diff --git a/larray/core/array.py b/larray/core/array.py
@@ -28,18 +28,13 @@
 
 # * use larray "utils" in LIAM2 (to avoid duplicated code)
 
-from collections import Iterable, Sequence, OrderedDict
+from collections import OrderedDict
 from itertools import product, chain, groupby, islice, repeat
 import os
 import sys
 import functools
 import warnings
 
-try:
-    import builtins
-except ImportError:
-    import __builtin__ as builtins
-
 import numpy as np
 import pandas as pd
 
@@ -60,10 +55,11 @@
 from larray.core.group import (Group, IGroup, LGroup, remove_nested_groups, _to_key, _to_keys,
                                _translate_sheet_name, _translate_group_key_hdf)
 from larray.core.axis import Axis, AxisReference, AxisCollection, X, _make_axis
-from larray.util.misc import (table2str, size2str, basestring, izip, rproduct, ReprString, duplicates,
-                              float_error_handler_factory, _isnoneslice, light_product, unique_list, common_type,
+from larray.util.misc import (table2str, size2str, ReprString,
+                              float_error_handler_factory, light_product, common_type,
                               renamed_to, deprecate_kwarg, LHDFStore, lazy_attribute, unique_multi, SequenceZip,
-                              Repeater, Product, ensure_no_numpy_type, PY2)
+                              Repeater, Product, ensure_no_numpy_type)
+from larray.util.compat import PY2, basestring, Iterable, Sequence, builtins
 from larray.util.options import _OPTIONS, DISPLAY_MAXLINES, DISPLAY_EDGEITEMS, DISPLAY_WIDTH, DISPLAY_PRECISION
 
 
@@ -8466,7 +8462,7 @@ def full_like(array, fill_value, title=None, dtype=None, order='K', meta=None):
 
 
 # XXX: would it be possible to generalize to multiple axes?
-def sequence(axis, initial=0, inc=None, mult=1, func=None, axes=None, title=None, meta=None):
+def sequence(axis, initial=0, inc=None, mult=None, func=None, axes=None, title=None, meta=None):
     r"""
     Creates an array by sequentially applying modifications to the array along axis.
 
@@ -8482,9 +8478,10 @@ def sequence(axis, initial=0, inc=None, mult=1, func=None, axes=None, title=None
     initial : scalar or Array, optional
         Value for the first label of axis. Defaults to 0.
     inc : scalar, Array, optional
-        Value to increment the previous value by. Defaults to 0 if mult is provided, 1 otherwise.
+        Value to increment the previous value by. Defaults to 1 unless mult is provided (in which case it defaults
+        to 0).
     mult : scalar, Array, optional
-        Value to multiply the previous value by. Defaults to 1.
+        Value to multiply the previous value by. Defaults to None.
     func : function/callable, optional
         Function to apply to the previous value. Defaults to None.
         Note that this is much slower than using inc and/or mult.
@@ -8574,10 +8571,14 @@ def sequence(axis, initial=0, inc=None, mult=1, func=None, axes=None, title=None
     meta = _handle_meta(meta, title)
 
     if inc is None:
-        inc = 1 if mult is 1 else 0
+        inc = 1 if mult is None else 0
+    if mult is None:
+        mult = 1
 
     # fast path for the most common case
-    if (mult is 1 and isinstance(inc, (int, np.integer)) and isinstance(initial, (int, np.integer)) and
+    integer_types = (int, np.integer)
+    if (isinstance(mult, integer_types) and mult == 1 and
+            isinstance(inc, integer_types) and isinstance(initial, integer_types) and
             func is None and axes is None):
         axis = _make_axis(axis)
         # stop is not included
diff --git a/larray/core/axis.py b/larray/core/axis.py
@@ -15,8 +15,9 @@
 from larray.core.group import (Group, LGroup, IGroup, IGroupMaker, _to_tick, _to_ticks, _to_key, _seq_summary,
                                _range_to_slice, _seq_group_to_name, _translate_group_key_hdf, remove_nested_groups)
 from larray.util.oset import *
-from larray.util.misc import (basestring, PY2, unicode, long, duplicates, array_lookup2, ReprString, index_by_id,
-                              renamed_to, common_type, LHDFStore, lazy_attribute, _isnoneslice, unique_multi, Product)
+from larray.util.misc import (duplicates, array_lookup2, ReprString, index_by_id, renamed_to, common_type, LHDFStore,
+                              lazy_attribute, _isnoneslice, unique_multi, Product)
+from larray.util.compat import (basestring, PY2, unicode, long)
 
 
 np_frompyfunc = np.frompyfunc
diff --git a/larray/core/group.py b/larray/core/group.py
@@ -12,8 +12,8 @@
 
 from larray.core.abstractbases import ABCAxis, ABCAxisReference, ABCArray
 from larray.util.oset import *
-from larray.util.misc import (basestring, PY2, unique, find_closing_chr, _parse_bound, _seq_summary, _isintstring,
-                              renamed_to, LHDFStore)
+from larray.util.misc import (unique, find_closing_chr, _parse_bound, _seq_summary, _isintstring, renamed_to, LHDFStore)
+from larray.util.compat import basestring, PY2
 
 
 def _slice_to_str(key, repr_func=str):
diff --git a/larray/core/metadata.py b/larray/core/metadata.py
@@ -2,7 +2,7 @@
 from __future__ import absolute_import, division, print_function
 
 from collections import OrderedDict
-from larray.util.misc import PY2, basestring
+from larray.util.compat import PY2, basestring
 
 
 if PY2:
diff --git a/larray/core/session.py b/larray/core/session.py
@@ -6,7 +6,7 @@
 import re
 import fnmatch
 import warnings
-from collections import OrderedDict, Iterable
+from collections import OrderedDict
 
 import numpy as np
 
@@ -15,7 +15,8 @@
 from larray.core.axis import Axis
 from larray.core.constants import nan
 from larray.core.array import Array, get_axes, ndtest, zeros, zeros_like, sequence, asarray
-from larray.util.misc import float_error_handler_factory, is_interactive_interpreter, renamed_to, inverseop, basestring
+from larray.util.misc import float_error_handler_factory, is_interactive_interpreter, renamed_to, inverseop
+from larray.util.compat import basestring, Iterable
 from larray.inout.session import ext_default_engine, get_file_handler
 
 
@@ -310,7 +311,7 @@ def __delitem__(self, key):
 
     # TODO: add a a meta property when Python 2.7 will be dropped
     def __getattr__(self, key):
-        if key is 'meta':
+        if key == 'meta':
             return self._meta
         elif key in self._objects:
             return self._objects[key]
@@ -319,7 +320,7 @@ def __getattr__(self, key):
 
     # TODO: implement meta.setter when Python 2.7 will be dropped
     def __setattr__(self, key, value):
-        if key is 'meta':
+        if key == 'meta':
             if not isinstance(value, (list, dict, OrderedDict, Metadata)):
                 raise TypeError("Expected list of pairs or dict or OrderedDict or Metadata object "
                                 "instead of {}".format(type(value).__name__))
diff --git a/larray/inout/csv.py b/larray/inout/csv.py
@@ -9,12 +9,11 @@
 import pandas as pd
 import numpy as np
 
-from larray.core.array import Array, asarray, ndtest
-from larray.core.axis import Axis
+from larray.core.array import Array, asarray
 from larray.core.constants import nan
-from larray.core.group import Group
 from larray.core.metadata import Metadata
-from larray.util.misc import skip_comment_cells, strip_rows, csv_open, deprecate_kwarg
+from larray.util.misc import skip_comment_cells, strip_rows, deprecate_kwarg
+from larray.util.compat import csv_open
 from larray.inout.session import register_file_handler
 from larray.inout.common import _get_index_col, FileHandler
 from larray.inout.pandas import df_asarray
diff --git a/larray/inout/misc.py b/larray/inout/misc.py
@@ -1,10 +1,10 @@
 from __future__ import absolute_import, print_function
 
-import numpy as np
 from pandas import DataFrame
 
 from larray.core.constants import nan
-from larray.util.misc import StringIO, deprecate_kwarg
+from larray.util.misc import deprecate_kwarg
+from larray.util.compat import StringIO
 from larray.inout.common import _get_index_col
 from larray.inout.pandas import df_asarray
 from larray.inout.csv import read_csv
diff --git a/larray/inout/pandas.py b/larray/inout/pandas.py
@@ -1,16 +1,15 @@
 from __future__ import absolute_import, print_function
 
 from itertools import product
-from collections import OrderedDict
 
 import numpy as np
 import pandas as pd
 
 from larray.core.array import Array
 from larray.core.axis import Axis, AxisCollection
-from larray.core.group import LGroup
 from larray.core.constants import nan
-from larray.util.misc import basestring, decode, unique
+from larray.util.misc import unique
+from larray.util.compat import basestring, decode, bytes
 
 
 def parse(s):
diff --git a/larray/inout/pickle.py b/larray/inout/pickle.py
@@ -7,7 +7,7 @@
 from larray.core.group import Group
 from larray.core.array import Array
 from larray.core.metadata import Metadata
-from larray.util.misc import pickle
+from larray.util.compat import pickle
 from larray.inout.session import register_file_handler
 from larray.inout.common import FileHandler
 
diff --git a/larray/inout/session.py b/larray/inout/session.py
@@ -1,5 +1,6 @@
 from __future__ import absolute_import, division, print_function
-from larray.util.misc import basestring
+
+from larray.util.compat import basestring
 
 
 handler_classes = {}
diff --git a/larray/inout/xw_excel.py b/larray/inout/xw_excel.py
@@ -16,7 +16,8 @@
 from larray.core.group import _translate_sheet_name
 from larray.inout.pandas import df_asarray
 from larray.inout.misc import from_lists
-from larray.util.misc import PY2, deprecate_kwarg
+from larray.util.misc import deprecate_kwarg
+from larray.util.compat import PY2
 
 
 string_types = (str,)
diff --git a/larray/inout/xw_reporting.py b/larray/inout/xw_reporting.py
@@ -2,7 +2,8 @@
 import warnings
 from collections import OrderedDict
 
-from larray.util.misc import PY2, _positive_integer, _validate_dir
+from larray.util.misc import _positive_integer, _validate_dir
+from larray.util.compat import PY2
 from larray.core.group import _translate_sheet_name
 from larray.core.array import asarray, zip_array_items
 from larray.example import load_example_data, EXAMPLE_EXCEL_TEMPLATES_DIR
diff --git a/larray/tests/test_array.py b/larray/tests/test_array.py
@@ -19,7 +19,8 @@
                     from_lists, from_string, open_excel, from_frame, sequence, nan, IGroup)
 from larray.inout.pandas import from_series
 from larray.core.axis import _to_ticks, _to_key
-from larray.util.misc import StringIO, LHDFStore
+from larray.util.misc import LHDFStore
+from larray.util.compat import StringIO
 from larray.core.metadata import Metadata
 
 
diff --git a/larray/tests/test_session.py b/larray/tests/test_session.py
@@ -11,7 +11,7 @@
                                  needs_xlwings, needs_pytables, needs_xlrd)
 from larray import (Session, Axis, Array, Group, isnan, zeros_like, ndtest, ones_like, ones, full,
                     local_arrays, global_arrays, arrays)
-from larray.util.misc import pickle, PY2
+from larray.util.compat import pickle, PY2
 
 
 def equal(o1, o2):
diff --git a/larray/util/compat.py b/larray/util/compat.py
@@ -0,0 +1,58 @@
+import sys
+
+try:
+    # the abstract base classes were moved to the abc sub-module in Python 3.3 but there is a backward compatibility
+    # layer for Python up to 3.7
+    from collections.abc import Iterable, Sequence
+except ImportError:
+    # needed for Python < 3.3 (including 2.7)
+    from collections import Iterable, Sequence
+
+try:
+    import builtins
+except ImportError:
+    import __builtin__ as builtins
+
+try:
+    from itertools import izip
+except ImportError:
+    izip = zip
+
+if sys.version_info[0] < 3:
+    basestring = basestring
+    bytes = str
+    unicode = unicode
+    long = long
+    PY2 = True
+else:
+    basestring = str
+    bytes = bytes
+    unicode = str
+    long = int
+    PY2 = False
+
+if PY2:
+    from StringIO import StringIO
+else:
+    from io import StringIO
+
+if PY2:
+    import cPickle as pickle
+else:
+    import pickle
+
+
+def csv_open(filename, mode='r'):
+    assert 'b' not in mode and 't' not in mode
+    if PY2:
+        return open(filename, mode + 'b')
+    else:
+        return open(filename, mode, newline='', encoding='utf8')
+
+
+def decode(s, encoding='utf-8', errors='strict'):
+    if isinstance(s, bytes):
+        return s.decode(encoding, errors)
+    else:
+        assert s is None or isinstance(s, unicode), "unexpected " + str(type(s))
+        return s
diff --git a/larray/util/misc.py b/larray/util/misc.py
@@ -15,42 +15,16 @@
 from itertools import product
 from collections import defaultdict
 
-try:
-    from itertools import izip
-except ImportError:
-    izip = zip
-
 import numpy as np
+import pandas as pd
+
+from larray.util.compat import PY2
+
 try:
     np.set_printoptions(legacy='1.13')
 except TypeError:
     pass
 
-import pandas as pd
-
-if sys.version_info[0] < 3:
-    basestring = basestring
-    bytes = str
-    unicode = unicode
-    long = long
-    PY2 = True
-else:
-    basestring = str
-    bytes = bytes
-    unicode = str
-    long = int
-    PY2 = False
-
-if PY2:
-    from StringIO import StringIO
-else:
-    from io import StringIO
-
-if PY2:
-    import cPickle as pickle
-else:
-    import pickle
-
 
 def is_interactive_interpreter():
     try:
@@ -62,22 +36,6 @@ def is_interactive_interpreter():
         return hasattr(sys, 'ps1')
 
 
-def csv_open(filename, mode='r'):
-    assert 'b' not in mode and 't' not in mode
-    if PY2:
-        return open(filename, mode + 'b')
-    else:
-        return open(filename, mode, newline='', encoding='utf8')
-
-
-def decode(s, encoding='utf-8', errors='strict'):
-    if isinstance(s, bytes):
-        return s.decode(encoding, errors)
-    else:
-        assert s is None or isinstance(s, unicode), "unexpected " + str(type(s))
-        return s
-
-
 def prod(values):
     return reduce(operator.mul, values, 1)
 
