# Copyright 2016-2021 Swiss National Supercomputing Centre (CSCS/ETH Zurich)
# ReFrame Project Developers. See the top-level LICENSE file for details.
#
# SPDX-License-Identifier: BSD-3-Clause
import builtins
import collections
import collections.abc
import functools
import importlib
import importlib.util
import itertools
import os
import re
import sys
import types
import weakref
from collections import UserDict
from . import typecheck as typ
def seconds_to_hms(seconds):
'''Convert time in seconds to hours, minutes and seconds.
:arg seconds: The time in seconds.
:returns: A three-element tuple such as ``(hours, minutes, seconds)``.
:meta private:
'''
m, s = divmod(seconds, 60)
h, m = divmod(m, 60)
return h, m, s
def _get_module_name(filename):
barename, _ = os.path.splitext(filename)
if os.path.basename(filename) == '__init__.py':
barename = os.path.dirname(filename)
if os.path.isabs(barename):
raise AssertionError('BUG: _get_module_name() '
'accepts relative paths only')
if filename.startswith('..'):
return os.path.basename(barename)
else:
return barename.replace(os.sep, '.')
def _do_import_module_from_file(filename, module_name=None):
module_name = module_name or _get_module_name(filename)
if module_name in sys.modules:
return sys.modules[module_name]
spec = importlib.util.spec_from_file_location(module_name, filename)
if spec is None:
raise ImportError("No module named '%s'" % module_name,
name=module_name, path=filename)
module = importlib.util.module_from_spec(spec)
sys.modules[module_name] = module
spec.loader.exec_module(module)
return module
[docs]def import_module_from_file(filename):
'''Import module from file.
:arg filename: The path to the filename of a Python module.
:returns: The loaded Python module.
'''
# Expand and sanitize filename
filename = os.path.abspath(os.path.expandvars(filename))
if os.path.isdir(filename):
filename = os.path.join(filename, '__init__.py')
# Express filename relative to reframe
rel_filename = os.path.relpath(filename, sys.path[0])
module_name = _get_module_name(rel_filename)
if rel_filename.startswith('..'):
# We cannot use the standard Python import mechanism here, because the
# module to import is outside the top-level package
return _do_import_module_from_file(filename, module_name)
# Extract module name if `filename` is under `site-packages/` or the
# Debian specific `dist-packages/`
site_packages = re.compile(r'.*(site|dist)-packages/(?P<rel_filename>.+)')
match = site_packages.search(filename)
if match:
module_name = _get_module_name(match['rel_filename'])
return importlib.import_module(module_name)
[docs]def allx(iterable):
'''Same as the built-in :py:func:`all`, except that it returns
:class:`False` if ``iterable`` is empty.
'''
# Generators must be treated specially, because there is no way to get
# their size without consuming their elements.
if isinstance(iterable, types.GeneratorType):
try:
head = next(iterable)
except StopIteration:
return False
else:
return all(itertools.chain([head], iterable))
if not isinstance(iterable, collections.abc.Iterable):
raise TypeError("'%s' object is not iterable" %
iterable.__class__.__name__)
return all(iterable) if iterable else False
[docs]def decamelize(s, delim='_'):
'''Decamelize a string.
For example, ``MyBaseClass`` will be converted to ``my_base_class``.
The delimiter may be changed by setting the ``delim`` argument.
:arg s: A string in camel notation.
:arg delim: The delimiter that will be used to separate words.
:returns: The converted string.
'''
if not isinstance(s, str):
raise TypeError('decamelize() requires a string argument')
if not s:
return ''
return re.sub(r'([a-z])([A-Z])', r'\1%s\2' % delim, s).lower()
def toalphanum(s):
'''Convert string ``s`` by replacing any non-alphanumeric character with
``_``.
:arg s: The string to convert.
:returns: The converted string.
:meta private:
'''
if not isinstance(s, str):
raise TypeError('toalphanum() requires a string argument')
if not s:
return ''
return re.sub(r'\W', '_', s)
[docs]def ppretty(value, htchar=' ', lfchar='\n', indent=4, basic_offset=0,
repr=builtins.repr):
'''Format value in a pretty way.
If value is a container, this function will recursively format the
container's elements.
:arg value: The value to be formatted.
:arg htchar: Horizontal-tab character.
:arg lfchar: Linefeed character.
:arg indent: Number of ``htchar`` characters for every indentation level.
:arg basic_offset: Basic offset for the representation, any additional
indentation space is added to the ``basic_offset``.
:arg repr: A :py:func:`repr`-like function that will be used for printing
values. This function is allowed to accept all the arguments of
:func:`ppretty` except the ``repr`` argument.
:returns: A formatted string of ``value``.
'''
ppretty2 = functools.partial(
ppretty, htchar=htchar, lfchar=lfchar, indent=indent,
basic_offset=basic_offset+1, repr=repr
)
nlch = lfchar + htchar * indent * (basic_offset + 1)
if isinstance(value, tuple):
if value == ():
return '()'
items = [nlch + ppretty2(item) for item in value]
return '(%s)' % (','.join(items) + lfchar +
htchar * indent * basic_offset)
elif isinstance(value, list):
if value == []:
return '[]'
items = [
nlch + ppretty2(item)
for item in value
]
return '[%s]' % (','.join(items) + lfchar +
htchar * indent * basic_offset)
elif isinstance(value, dict):
if value == {}:
return '{}'
items = [
nlch + repr(key) + ': ' + ppretty2(value[key]) for key in value
]
return '{%s}' % (','.join(items) + lfchar +
htchar * indent * basic_offset)
elif isinstance(value, set):
if value == set():
return 'set()'
items = [nlch + ppretty2(item) for item in value]
return '{%s}' % (','.join(items) + lfchar +
htchar * indent * basic_offset)
else:
try:
return repr(value, htchar, lfchar, indent, basic_offset)
except TypeError:
# Not our custom repr()
return repr(value)
def _tracked_repr(func):
objects = set()
@functools.wraps(func)
def _repr(obj, *args, **kwargs):
addr = id(obj)
if addr in objects:
return f'{type(obj).__name__}(...)@{hex(addr)}'
# Do not track builtin objects
if hasattr(obj, '__dict__'):
objects.add(addr)
return func(obj, *args, **kwargs)
return _repr
[docs]@_tracked_repr
def repr(obj, htchar=' ', lfchar='\n', indent=4, basic_offset=0):
'''A |builtin.repr|_ replacement function for debugging purposes printing
all object attributes recursively.
This function does not follow the standard |builtin.repr|_ convention, but
it prints each object as a set of key/value pairs along with its memory
location. It also keeps track of the already visited objects, and
abbreviates their representation.
:arg obj: The object to be dumped.
For the rest of the arguments, see :func:`ppretty`.
:returns: The formatted object dump.
.. _builtin.repr: https://docs.python.org/3/library/functions.html#repr
.. |builtin.repr| replace:: :js:func:`repr()`
'''
if (isinstance(obj, list) or isinstance(obj, tuple) or
isinstance(obj, set) or isinstance(obj, dict)):
return ppretty(obj, basic_offset=basic_offset, repr=repr)
if not hasattr(obj, '__dict__'):
return builtins.repr(obj)
r = ppretty(obj.__dict__, htchar, lfchar, indent, basic_offset, repr)
return f'{type(obj).__name__}({r})@{hex(id(obj))}'
def _is_builtin_type(cls):
# NOTE: The set of types is copied from the copy.deepcopy() implementation
builtin_types = (type(None), int, float, bool, complex, str, tuple,
bytes, frozenset, type, range, slice, property,
type(Ellipsis), type(NotImplemented), weakref.ref,
types.BuiltinFunctionType, types.FunctionType)
if not isinstance(cls, type):
return False
return any(t == cls for t in builtin_types)
def _is_function_type(cls):
return (isinstance(cls, types.BuiltinFunctionType) or
isinstance(cls, types.FunctionType))
[docs]def attr_validator(validate_fn):
'''Validate object attributes recursively.
This returns a function which you can call with the object to check. It
will return :class:`True` if the :func:`validate_fn` returns :class:`True`
for all object attributes recursively. If the object to be validated is an
iterable, its elements will be validated individually.
:arg validate_fn: A callable that validates an object. It takes a single
argument, which is the object to validate.
:returns: A validation function that will perform the actual validation.
It accepts a single argument, which is the object to validate. It
returns a two-element tuple, containing the result of the validation
as a boolean and a formatted string indicating the faulty attribute.
.. note::
Objects defining :attr:`__slots__` are passed directly to the
``validate_fn`` function.
.. versionadded:: 3.3
'''
# Already visited objects
visited = set()
depth = 0
def _do_validate(obj, path=None):
def _fmt(path):
ret = ''
for p in path:
t, name = p
if t == 'A':
ret += f'.{name}'
elif t == 'I':
ret += f'[{name}]'
elif t == 'K':
ret += f'[{name!r}]'
# Remove leading '.'
return ret[1:] if ret[0] == '.' else ret
nonlocal depth
def _clean_cache():
nonlocal depth
depth -= 1
if depth == 0:
# We are exiting the top-level call
visited.clear()
depth += 1
visited.add(id(obj))
if path is None:
path = [('A', type(obj).__name__)]
if isinstance(obj, dict):
for k, v in obj.items():
if id(v) in visited:
continue
path.append(('K', k))
valid, _ = _do_validate(v, path)
if not valid:
_clean_cache()
return False, _fmt(path)
path.pop()
_clean_cache()
return True, _fmt(path)
if (isinstance(obj, list) or
isinstance(obj, tuple) or
isinstance(obj, set)):
for i, x in enumerate(obj):
if id(x) in visited:
continue
path.append(('I', i))
valid, _ = _do_validate(x, path)
if not valid:
_clean_cache()
return False, _fmt(path)
path.pop()
_clean_cache()
return True, _fmt(path)
valid = validate_fn(obj)
if not valid:
_clean_cache()
return False, _fmt(path)
# Stop here if obj is a built-in type
if isinstance(obj, type) and _is_builtin_type(obj):
return True, _fmt(path)
if hasattr(obj, '__dict__'):
for k, v in obj.__dict__.items():
if id(v) in visited:
continue
path.append(('A', k))
valid, _ = _do_validate(v, path)
if not valid:
_clean_cache()
return False, _fmt(path)
path.pop()
_clean_cache()
return True, _fmt(path)
return _do_validate
[docs]def is_copyable(obj):
'''Check if an object can be copied with :py:func:`copy.deepcopy`, without
performing the copy.
This is a superset of :func:`is_picklable`. It returns :class:`True` also
in the following cases:
- The object defines a :func:`__copy__` method.
- The object defines a :func:`__deepcopy__` method.
- The object is a function.
- The object is a builtin type.
.. versionadded:: 3.3
'''
if hasattr(obj, '__copy__') or hasattr(obj, '__deepcopy__'):
return True
if _is_function_type(obj):
return True
if _is_builtin_type(obj):
return True
return is_picklable(obj)
[docs]def is_picklable(obj):
'''Check if an object can be pickled.
.. versionadded:: 3.3
'''
if isinstance(obj, type):
return False
if hasattr(obj, '__reduce_ex__'):
try:
obj.__reduce_ex__(4)
return True
except TypeError:
return False
if hasattr(obj, '__reduce__'):
try:
obj.__reduce__()
return True
except TypeError:
return False
return False
[docs]def shortest(*iterables):
'''Return the shortest sequence.
This function raises a :py:class:`TypeError` if any of the iterables is
not |Sized|_.
:arg iterables: The iterables to check.
:returns: The shortest iterable.
.. _Sized: https://docs.python.org/3/library/collections.abc.html#collections.abc.Sized # noqa: E501
.. |Sized| replace:: :class:`Sized`
'''
ret = None
for seq in iterables:
if not isinstance(seq, collections.abc.Sized):
raise TypeError(f'expected a sized iterable: {seq}')
if ret is None:
ret = seq
continue
if len(seq) < len(ret):
ret = seq
return ret
[docs]def longest(*iterables):
'''Return the longest sequence.
This function raises a :py:class:`TypeError` if any of the iterables is
not |Sized|_.
:arg iterables: The iterables to check.
:returns: The longest iterable.
'''
ret = None
for seq in iterables:
if not isinstance(seq, collections.abc.Sized):
raise TypeError(f'expected a sized iterable: {seq}')
if ret is None:
ret = seq
continue
if len(seq) > len(ret):
ret = seq
return ret
[docs]def find_modules(substr, environ_mapping=None):
'''Return all modules in the current system that contain ``substr`` in
their name.
This function is a generator and will yield tuples of partition,
environment and module combinations for each partition of the current
system and for each environment of a partition.
The ``environ_mapping`` argument allows you to map module name patterns to
ReFrame environments. This is useful for flat module name schemes, in
order to avoid incompatible combinations of modules and environments.
You can use this function to parametrize regression tests over the
available environment modules. The following example will generate tests
for all the available ``netcdf`` packages in the system:
.. code:: python
@rfm.parameterized_test(*find_modules('netcdf'))
class MyTest(rfm.RegressionTest):
def __init__(self, s, e, m):
self.descr = f'{s}, {e}, {m}'
self.valid_systems = [s]
self.valid_prog_environs = [e]
self.modules = [m]
...
The following example shows the use of ``environ_mapping`` with flat
module name schemes. In this example, the toolchain for which the package
was built is encoded in the module's name. Using the ``environ_mapping``
argument we can map module name patterns to ReFrame environments, so that
invalid combinations are pruned:
.. code:: python
my_find_modules = functools.partial(find_modules, environ_mapping={
r'.*CrayGNU.*': {'PrgEnv-gnu'},
r'.*CrayIntel.*': {'PrgEnv-intel'},
r'.*CrayCCE.*': {'PrgEnv-cray'}
})
@rfm.parameterized_test(*my_find_modules('GROMACS'))
class MyTest(rfm.RegressionTest):
def __init__(self, s, e, m):
self.descr = f'{s}, {e}, {m}'
self.valid_systems = [s]
self.valid_prog_environs = [e]
self.modules = [m]
...
:arg substr: A substring that the returned module names must contain.
:arg environ_mapping: A dictionary mapping regular expressions to
environment names.
:returns: An iterator that iterates over tuples of the module, partition
and environment name combinations that were found.
'''
import reframe.core.runtime as rt
if not isinstance(substr, str):
raise TypeError("'substr' argument must be a string")
if (environ_mapping is not None and
not isinstance(environ_mapping, typ.Dict[str, str])):
raise TypeError(
"'environ_mapping' argument must be of type Dict[str,str]"
)
def _is_valid_for_env(m, e):
if environ_mapping is None:
return True
for patt, environs in environ_mapping.items():
if re.match(patt, m) and e in environs:
return True
return False
ms = rt.runtime().modules_system
current_system = rt.runtime().system
snap0 = rt.snapshot()
for p in current_system.partitions:
for e in p.environs:
rt.loadenv(p.local_env, e)
modules = ms.available_modules(substr)
snap0.restore()
for m in modules:
if _is_valid_for_env(m, e.name):
yield (p.fullname, e.name, m)
[docs]class ScopedDict(UserDict):
'''This is a special dictionary that imposes scopes on its keys.
When a key is not found, it will be searched up in the scope hierarchy.
If not found even at the global scope, a :class:`KeyError` will be raised.
A scoped dictionary is initialized using a two-level normal dictionary
that defines the different scopes and the keys inside them. Scopes can be
nested by concatenating them using the ``:`` separator by default:
``scope:subscope``. Below is an example of a scoped dictionary that also
demonstrates key lookup:
.. code-block:: python
d = ScopedDict({
'a': {'k1': 1, 'k2': 2},
'a:b': {'k1': 3, 'k3': 4},
'*': {'k1': 7, 'k3': 9, 'k4': 10}
})
assert d['a:k1'] == 1 # resolved in the scope 'a'
assert d['a:k3'] == 9 # resolved in the global scope
assert d['a:b:k1'] == 3 # resolved in the scope 'a:b'
assert d['a:b:k2'] == 2 # resolved in the scope 'a'
assert d['a:b:k4'] == 10 # resolved in the global scope
d['a:k5'] # KeyError
d['*:k2'] # KeyError
If no scope is specified in the key lookup, the global scope is assumed.
For example, ``d['k1']`` will return ``7``. The syntaxes ``d[':k1']`` and
``d['*:k1']`` are all equivalent.
If you try to retrieve a whole scope, e.g., ``d['a:b']``,
:class:`KeyError` will be raised.
Key deletion follows the same resolution mechanism as key retrieval,
except that you are allowed to delete whole scopes. For example, ``del
d['*']`` will delete the global scope, such that subsequent access of
``d['a:k3']`` will raise a :class:`KeyError`. If a key specification
matches both a key and scope, the key will be deleted and not the scope.
:arg mapping: A two-level mapping of the form
.. code-block:: python
{
scope1: {k1: v1, k2: v2},
scope2: {k1: v1, k3: v3}
}
Both the scope keys and the actual dictionary keys must be
strings, otherwise a :class:`TypeError` will be raised.
:arg scope_sep: A character that separates the scopes.
:arg global_scope: A key that represents the global scope.
'''
def __init__(self, mapping={}, scope_sep=':', global_scope='*'):
super().__init__(mapping)
self._scope_sep = scope_sep
self._global_scope = global_scope
@property
def scope_separator(self):
'''The scope separator of this dictionary.'''
return self._scope_sep
@property
def global_scope_mark(self):
'''The key representing the global scope of this dictionary.'''
return self._global_scope
[docs] def update(self, other):
'''Update this dictionary from the values of a two-level mapping as
described above.
:arg other: A two-level mapping defining scopes and keys.
'''
if not isinstance(other, collections.abc.Mapping):
raise TypeError('ScopedDict may only be initialized '
'from a mapping type')
for scope, scope_dict in other.items():
self._check_scope_type(scope, scope_dict)
self.data.setdefault(scope, {})
for k, v in scope_dict.items():
self.data[scope][k] = v
def __str__(self):
# just return the internal dictionary
return str(self.data)
def _check_scope_type(self, key, value):
if not isinstance(key, str):
raise TypeError('scope keys in a ScopedDict must be strings')
if not isinstance(value, collections.abc.Mapping):
raise TypeError('scope namespaces must be mappings')
for k in value.keys():
if not isinstance(k, str):
raise TypeError('keys must be strings')
def _keyinfo(self, key):
key_parts = key.rsplit(self._scope_sep, maxsplit=1)
if len(key_parts) == 2:
return (key_parts[0], key_parts[1])
else:
return (self._global_scope, key_parts[0])
def _parent_scope(self, scope):
scope_parts = scope.rsplit(':', maxsplit=1)[:-1]
return scope_parts[0] if scope_parts else self._global_scope
def _lookup(self, key):
scope, lookup_key = self._keyinfo(key)
while scope != self._global_scope:
if scope in self.data and lookup_key in self.data[scope]:
return self.data[scope][lookup_key]
scope = self._parent_scope(scope)
# last chance to find the key
if scope in self.data and lookup_key in self.data[scope]:
return self.data[scope][lookup_key]
raise KeyError(str(key))
def __iter__(self):
for scope, scope_dict in self.data.items():
for k in scope_dict.keys():
yield self._scope_sep.join([scope, k])
def __contains__(self, key):
try:
self._lookup(key)
except KeyError:
return False
else:
return True
def __getitem__(self, key):
try:
return self._lookup(key)
except KeyError:
return self.__missing__(key)
def __setitem__(self, key, value):
scope, lookup_key = self._keyinfo(key)
if scope not in self.data:
# create the scope if does not exist
self.data[scope] = {}
self.data[scope][lookup_key] = value
def __delitem__(self, key):
'''Deletes either a key or a scope if key refers to a scope.
If key refers to both a scope and a key, the key will be deleted.
If key refers to scope, the whole scope entry will be deleted.
If not, the exact key requested will be deleted.
No key resolution will be performed.'''
scope, lookup_key = self._keyinfo(key)
if scope in self.data and lookup_key in self.data[scope]:
del self.data[scope][lookup_key]
elif key in self.data:
# key is a scope
del self.data[key]
else:
raise KeyError(str(key))
def __missing__(self, key):
raise KeyError(str(key))
[docs]@functools.total_ordering
class OrderedSet(collections.abc.MutableSet):
'''An ordered set.
This container behaves like a normal set but remembers the insertion order
of its elements. It can also inter-operate with standard Python sets.
Operations between ordered sets respect the order of the elements of the
operands. For example, if ``x`` and ``y`` are both ordered sets, then ``x
| y`` will be a new ordered set with the (unique) elements of ``x`` and
``y`` in the order they appear in ``x`` and ``y``. The same holds for all
the other set operations.
'''
def __init__(self, *args):
# We need to allow construction without arguments
if not args:
iterable = []
elif len(args) == 1:
iterable = args[0]
else:
# We use the exact same error message as for the built-in set
raise TypeError('%s expected at most 1 arguments, got %s' %
type(self).__name__, len(args))
if not isinstance(iterable, collections.abc.Iterable):
raise TypeError("'%s' object is not iterable" %
type(iterable).__name__)
# We implement an ordered set through the keys of an OrderedDict;
# its values are all set to None
self.__data = collections.OrderedDict(
itertools.zip_longest(iterable, [], fillvalue=None)
)
def __repr__(self):
vals = self.__data.keys()
if not vals:
return type(self).__name__ + '()'
else:
return '{' + ', '.join(repr(v) for v in vals) + '}'
# Container i/face
def __contains__(self, item):
return item in self.__data
def __iter__(self):
return iter(self.__data)
def __len__(self):
return len(self.__data)
# Set i/face
def __eq__(self, other):
if isinstance(other, OrderedSet):
if len(self) != len(other):
return False
for x, y in zip(self, other):
if x != y:
return False
return True
elif isinstance(other, collections.abc.Set):
return set(self.__data.keys()) == other
else:
return NotImplemented
def __gt__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
return set(self.__data.keys()) > other
def __and__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
ret = type(self)()
for x in shortest(self, other):
if x in self and x in other:
ret.add(x)
return ret
def __or__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
ret = type(self)()
for x in itertools.chain(self, other):
ret.add(x)
return ret
def __sub__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
ret = type(self)(self.__data.keys())
for x in other:
if x in ret:
ret.remove(x)
return ret
def __xor__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
ret = type(self)()
for x in itertools.chain(self, other):
if x in self and x in other:
continue
ret.add(x)
return ret
[docs] def isdisjoint(self, other):
'''See same method in :py:class:`set`.'''
if not isinstance(other, collections.abc.Set):
return NotImplemented
return set(self.__data.keys()).isdisjoint(other)
[docs] def issubset(self, other):
'''See same method in :py:class:`set`.'''
return self <= other
[docs] def issuperset(self, other):
'''See same method in :py:class:`set`.'''
return self >= other
[docs] def symmetric_difference(self, other):
'''See same method in :py:class:`set`.'''
return self ^ other
[docs] def union(self, *others):
'''See same method in :py:class:`set`.'''
ret = type(self)(self)
for s in others:
ret |= s
return ret
[docs] def intersection(self, *others):
'''See same method in :py:class:`set`.'''
ret = type(self)(self)
for s in others:
ret &= s
return ret
[docs] def difference(self, *others):
'''See same method in :py:class:`set`.'''
ret = type(self)(self)
for s in others:
ret -= s
return ret
# MutableSet i/face
[docs] def add(self, elem):
'''See same method in :py:class:`set`.'''
self.__data[elem] = None
[docs] def remove(self, elem):
'''See same method in :py:class:`set`.'''
del self.__data[elem]
[docs] def discard(self, elem):
'''See same method in :py:class:`set`.'''
try:
self.remove(elem)
except KeyError:
pass
[docs] def pop(self):
'''See same method in :py:class:`set`.'''
return self.__data.popitem()[0]
[docs] def clear(self):
'''See same method in :py:class:`set`.'''
self.__data.clear()
def __ior__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
for e in other:
self.add(e)
return self
def __iand__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
discard_list = [e for e in self if e not in other]
for e in discard_list:
self.discard(e)
return self
def __isub__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
for e in other:
self.discard(e)
return self
def __ixor__(self, other):
if not isinstance(other, collections.abc.Set):
return NotImplemented
discard_list = [e for e in self if e in other]
for e in discard_list:
self.discard(e)
return self
# Other functions
def __reversed__(self):
return reversed(self.__data.keys())
[docs]class SequenceView(collections.abc.Sequence):
'''A read-only view of a sequence.
See :py:class:`collections.abc.Sequence` for a list of supported of
operations.
:arg container: The container to create a view on.
:raises TypeError: If the container does not fulfill the
:py:class:`collections.abc.Sequence` interface.
'''
def __init__(self, container):
if not isinstance(container, collections.abc.Sequence):
raise TypeError('container must be of type Sequence')
self.__container = container
[docs] def count(self, value):
'''Count occurrences of ``value`` in the container.
:arg value: The value to search for.
:returns: The number of occurrences.
'''
return self.__container.count(value)
[docs] def index(self, value, start=0, stop=None):
'''Return the first index of ``value``.
:arg value: The value to search for.
:arg start: The position where the search starts.
:arg stop: The position where the search stops. The element at this
position is not looked at. If :class:`None`, this equals to the
sequence's length.
:returns: The index of the first element found that equals ``value``.
:raises ValueError: if the value is not present.
'''
if stop is None:
stop = len(self.__container)
return self.__container.index(value, start, stop)
def __contains__(self, value):
return self.__container.__contains__(value)
def __getitem__(self, index):
return self.__container.__getitem__(index)
def __iter__(self):
return self.__container.__iter__()
def __len__(self):
return self.__container.__len__()
def __reversed__(self):
return self.__container.__reversed__()
def __add__(self, other):
if not isinstance(other, collections.abc.Sequence):
return NotImplemented
return SequenceView(self.__container + other)
def __iadd__(self, other):
return NotImplemented
def __eq__(self, other):
if isinstance(other, SequenceView):
return self.__container == other.__container
return self.__container == other
def __repr__(self):
return '%s(%r)' % (type(self).__name__, self.__container)
def __str__(self):
return str(self.__container)
[docs]class MappingView(collections.abc.Mapping):
'''A read-only view of a mapping.
See :py:class:`collections.abc.Mapping` for a list of supported of
operations.
'''
def __init__(self, mapping):
if not isinstance(mapping, collections.abc.Mapping):
raise TypeError('container must be of type Mapping')
self.__mapping = mapping
[docs] def get(self, key, default=None):
'''Return the value mapped to ``key`` or ``default``, if ``key`` does
not exist.
:arg key: The key to look up.
:arg default: The default value to return if the key is not present.
:returns: The value associated to the requested key.
'''
return self.__mapping.get(key, default)
[docs] def keys(self):
'''Return a set-like object providing a view on the underlying
mapping's keys.'''
return self.__mapping.keys()
[docs] def items(self):
'''Return a set-like object providing a view on the underlying
mapping's items.'''
return self.__mapping.items()
[docs] def values(self):
'''Return a set-like object providing a view on the underlying
mapping's values.'''
return self.__mapping.values()
def __contains__(self, key):
return self.__mapping.__contains__(key)
def __getitem__(self, key):
return self.__mapping.__getitem__(key)
def __iter__(self):
return self.__mapping.__iter__()
def __len__(self):
return self.__mapping.__len__()
def __eq__(self, other):
if isinstance(other, MappingView):
return self.__mapping == other.__mapping
return self.__mapping.__eq__(other)
def __repr__(self):
return '%s(%r)' % (type(self).__name__, self.__mapping)
def __str__(self):
return str(self.__mapping)