Source code for openquake.baselib.python3compat

# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright (C) 2015-2021 GEM Foundation

# OpenQuake is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# OpenQuake is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with OpenQuake.  If not, see <>.

Compatibility layer for Python 2 and 3. Mostly copied from six and future,
but reduced to the subset of utilities needed by GEM. This is done to
avoid an external dependency.
import math
import builtins
import numpy

[docs]def encode(val): """ Encode a string assuming the encoding is UTF-8. :param: a unicode or bytes object :returns: bytes """ if isinstance(val, (list, tuple, numpy.ndarray)): # encode a sequence of strings return [encode(v) for v in val] elif isinstance(val, str): return val.encode('utf-8') else: # assume it was an already encoded object return val
[docs]def decode(val): """ Decode an object assuming the encoding is UTF-8. :param: a unicode or bytes object :returns: a unicode object """ if isinstance(val, (list, tuple, numpy.ndarray)): return [decode(v) for v in val] elif hasattr(val, 'decode'): # assume it is an encoded bytes object return val.decode('utf-8') else: return str(val)
[docs]def zip(arg, *args): for a in args: assert len(a) == len(arg), (len(a), len(arg)) return, *args)
[docs]def round(x, d=0): p = 10 ** d return float(math.floor((x * p) + math.copysign(0.5, x))) / p
[docs]def raise_(tp, value=None, tb=None): """ A function that matches the Python 2.x ``raise`` statement. This allows re-raising exceptions with the cls value and traceback on Python 2 and 3. """ if value is not None and isinstance(tp, Exception): raise TypeError("instance exception may not have a separate value") if value is not None: exc = tp(value) else: exc = tp if exc.__traceback__ is not tb: raise exc.with_traceback(tb) raise exc
# the following is used in the SMTK # copied from
[docs]def with_metaclass(meta, *bases): """ Returns an instance of meta inheriting from the given bases. To be used to replace the __metaclass__ syntax. """ class metaclass(meta): __call__ = type.__call__ __init__ = type.__init__ def __new__(mcl, name, this_bases, d): if this_bases is None: return type.__new__(mcl, name, (), d) return meta(name, bases, d) return metaclass('temporary_class', None, {})