Current File : //usr/lib/python3/dist-packages/pip/_vendor/distlib/metadata.py
# -*- coding: utf-8 -*-
#
# Copyright (C) 2012 The Python Software Foundation.
# See LICENSE.txt and CONTRIBUTORS.txt.
#
"""Implementation of the Metadata for Python packages PEPs.

Supports all metadata formats (1.0, 1.1, 1.2, 1.3/2.1 and 2.2).
"""
from __future__ import unicode_literals

import codecs
from email import message_from_file
import json
import logging
import re


from . import DistlibException, __version__
from .compat import StringIO, string_types, text_type
from .markers import interpret
from .util import extract_by_key, get_extras
from .version import get_scheme, PEP440_VERSION_RE

logger = logging.getLogger(__name__)


class MetadataMissingError(DistlibException):
    """A required metadata is missing"""


class MetadataConflictError(DistlibException):
    """Attempt to read or write metadata fields that are conflictual."""


class MetadataUnrecognizedVersionError(DistlibException):
    """Unknown metadata version number."""


class MetadataInvalidError(DistlibException):
    """A metadata value is invalid"""

# public API of this module
__all__ = ['Metadata', 'PKG_INFO_ENCODING', 'PKG_INFO_PREFERRED_VERSION']

# Encoding used for the PKG-INFO files
PKG_INFO_ENCODING = 'utf-8'

# preferred version. Hopefully will be changed
# to 1.2 once PEP 345 is supported everywhere
PKG_INFO_PREFERRED_VERSION = '1.1'

_LINE_PREFIX_1_2 = re.compile('\n       \\|')
_LINE_PREFIX_PRE_1_2 = re.compile('\n        ')
_241_FIELDS = ('Metadata-Version', 'Name', 'Version', 'Platform',
               'Summary', 'Description',
               'Keywords', 'Home-page', 'Author', 'Author-email',
               'License')

_314_FIELDS = ('Metadata-Version', 'Name', 'Version', 'Platform',
               'Supported-Platform', 'Summary', 'Description',
               'Keywords', 'Home-page', 'Author', 'Author-email',
               'License', 'Classifier', 'Download-URL', 'Obsoletes',
               'Provides', 'Requires')

_314_MARKERS = ('Obsoletes', 'Provides', 'Requires', 'Classifier',
                'Download-URL')

_345_FIELDS = ('Metadata-Version', 'Name', 'Version', 'Platform',
               'Supported-Platform', 'Summary', 'Description',
               'Keywords', 'Home-page', 'Author', 'Author-email',
               'Maintainer', 'Maintainer-email', 'License',
               'Classifier', 'Download-URL', 'Obsoletes-Dist',
               'Project-URL', 'Provides-Dist', 'Requires-Dist',
               'Requires-Python', 'Requires-External')

_345_MARKERS = ('Provides-Dist', 'Requires-Dist', 'Requires-Python',
                'Obsoletes-Dist', 'Requires-External', 'Maintainer',
                'Maintainer-email', 'Project-URL')

_426_FIELDS = ('Metadata-Version', 'Name', 'Version', 'Platform',
               'Supported-Platform', 'Summary', 'Description',
               'Keywords', 'Home-page', 'Author', 'Author-email',
               'Maintainer', 'Maintainer-email', 'License',
               'Classifier', 'Download-URL', 'Obsoletes-Dist',
               'Project-URL', 'Provides-Dist', 'Requires-Dist',
               'Requires-Python', 'Requires-External', 'Private-Version',
               'Obsoleted-By', 'Setup-Requires-Dist', 'Extension',
               'Provides-Extra')

_426_MARKERS = ('Private-Version', 'Provides-Extra', 'Obsoleted-By',
                'Setup-Requires-Dist', 'Extension')

# See issue #106: Sometimes 'Requires' and 'Provides' occur wrongly in
# the metadata. Include them in the tuple literal below to allow them
# (for now).
# Ditto for Obsoletes - see issue #140.
_566_FIELDS = _426_FIELDS + ('Description-Content-Type',
                             'Requires', 'Provides', 'Obsoletes')

_566_MARKERS = ('Description-Content-Type',)

_643_MARKERS = ('Dynamic', 'License-File')

_643_FIELDS = _566_FIELDS + _643_MARKERS

_ALL_FIELDS = set()
_ALL_FIELDS.update(_241_FIELDS)
_ALL_FIELDS.update(_314_FIELDS)
_ALL_FIELDS.update(_345_FIELDS)
_ALL_FIELDS.update(_426_FIELDS)
_ALL_FIELDS.update(_566_FIELDS)
_ALL_FIELDS.update(_643_FIELDS)

EXTRA_RE = re.compile(r'''extra\s*==\s*("([^"]+)"|'([^']+)')''')


def _version2fieldlist(version):
    if version == '1.0':
        return _241_FIELDS
    elif version == '1.1':
        return _314_FIELDS
    elif version == '1.2':
        return _345_FIELDS
    elif version in ('1.3', '2.1'):
        # avoid adding field names if already there
        return _345_FIELDS + tuple(f for f in _566_FIELDS if f not in _345_FIELDS)
    elif version == '2.0':
        raise ValueError('Metadata 2.0 is withdrawn and not supported')
        # return _426_FIELDS
    elif version == '2.2':
        return _643_FIELDS
    raise MetadataUnrecognizedVersionError(version)


def _best_version(fields):
    """Detect the best version depending on the fields used."""
    def _has_marker(keys, markers):
        return any(marker in keys for marker in markers)

    keys = [key for key, value in fields.items() if value not in ([], 'UNKNOWN', None)]
    possible_versions = ['1.0', '1.1', '1.2', '1.3', '2.1', '2.2']  # 2.0 removed

    # first let's try to see if a field is not part of one of the version
    for key in keys:
        if key not in _241_FIELDS and '1.0' in possible_versions:
            possible_versions.remove('1.0')
            logger.debug('Removed 1.0 due to %s', key)
        if key not in _314_FIELDS and '1.1' in possible_versions:
            possible_versions.remove('1.1')
            logger.debug('Removed 1.1 due to %s', key)
        if key not in _345_FIELDS and '1.2' in possible_versions:
            possible_versions.remove('1.2')
            logger.debug('Removed 1.2 due to %s', key)
        if key not in _566_FIELDS and '1.3' in possible_versions:
            possible_versions.remove('1.3')
            logger.debug('Removed 1.3 due to %s', key)
        if key not in _566_FIELDS and '2.1' in possible_versions:
            if key != 'Description':  # In 2.1, description allowed after headers
                possible_versions.remove('2.1')
                logger.debug('Removed 2.1 due to %s', key)
        if key not in _643_FIELDS and '2.2' in possible_versions:
            possible_versions.remove('2.2')
            logger.debug('Removed 2.2 due to %s', key)
        # if key not in _426_FIELDS and '2.0' in possible_versions:
            # possible_versions.remove('2.0')
            # logger.debug('Removed 2.0 due to %s', key)

    # possible_version contains qualified versions
    if len(possible_versions) == 1:
        return possible_versions[0]   # found !
    elif len(possible_versions) == 0:
        logger.debug('Out of options - unknown metadata set: %s', fields)
        raise MetadataConflictError('Unknown metadata set')

    # let's see if one unique marker is found
    is_1_1 = '1.1' in possible_versions and _has_marker(keys, _314_MARKERS)
    is_1_2 = '1.2' in possible_versions and _has_marker(keys, _345_MARKERS)
    is_2_1 = '2.1' in possible_versions and _has_marker(keys, _566_MARKERS)
    # is_2_0 = '2.0' in possible_versions and _has_marker(keys, _426_MARKERS)
    is_2_2 = '2.2' in possible_versions and _has_marker(keys, _643_MARKERS)
    if int(is_1_1) + int(is_1_2) + int(is_2_1) + int(is_2_2) > 1:
        raise MetadataConflictError('You used incompatible 1.1/1.2/2.1/2.2 fields')

    # we have the choice, 1.0, or 1.2, 2.1 or 2.2
    #   - 1.0 has a broken Summary field but works with all tools
    #   - 1.1 is to avoid
    #   - 1.2 fixes Summary but has little adoption
    #   - 2.1 adds more features
    #   - 2.2 is the latest
    if not is_1_1 and not is_1_2 and not is_2_1 and not is_2_2:
        # we couldn't find any specific marker
        if PKG_INFO_PREFERRED_VERSION in possible_versions:
            return PKG_INFO_PREFERRED_VERSION
    if is_1_1:
        return '1.1'
    if is_1_2:
        return '1.2'
    if is_2_1:
        return '2.1'
    # if is_2_2:
        # return '2.2'

    return '2.2'

# This follows the rules about transforming keys as described in
# https://www.python.org/dev/peps/pep-0566/#id17
_ATTR2FIELD = {
    name.lower().replace("-", "_"): name for name in _ALL_FIELDS
}
_FIELD2ATTR = {field: attr for attr, field in _ATTR2FIELD.items()}

_PREDICATE_FIELDS = ('Requires-Dist', 'Obsoletes-Dist', 'Provides-Dist')
_VERSIONS_FIELDS = ('Requires-Python',)
_VERSION_FIELDS = ('Version',)
_LISTFIELDS = ('Platform', 'Classifier', 'Obsoletes',
               'Requires', 'Provides', 'Obsoletes-Dist',
               'Provides-Dist', 'Requires-Dist', 'Requires-External',
               'Project-URL', 'Supported-Platform', 'Setup-Requires-Dist',
               'Provides-Extra', 'Extension', 'License-File')
_LISTTUPLEFIELDS = ('Project-URL',)

_ELEMENTSFIELD = ('Keywords',)

_UNICODEFIELDS = ('Author', 'Maintainer', 'Summary', 'Description')

_MISSING = object()

_FILESAFE = re.compile('[^A-Za-z0-9.]+')


def _get_name_and_version(name, version, for_filename=False):
    """Return the distribution name with version.

    If for_filename is true, return a filename-escaped form."""
    if for_filename:
        # For both name and version any runs of non-alphanumeric or '.'
        # characters are replaced with a single '-'.  Additionally any
        # spaces in the version string become '.'
        name = _FILESAFE.sub('-', name)
        version = _FILESAFE.sub('-', version.replace(' ', '.'))
    return '%s-%s' % (name, version)


class LegacyMetadata(object):
    """The legacy metadata of a release.

    Supports versions 1.0, 1.1, 1.2, 2.0 and 1.3/2.1 (auto-detected). You can
    instantiate the class with one of these arguments (or none):
    - *path*, the path to a metadata file
    - *fileobj* give a file-like object with metadata as content
    - *mapping* is a dict-like object
    - *scheme* is a version scheme name
    """
    # TODO document the mapping API and UNKNOWN default key

    def __init__(self, path=None, fileobj=None, mapping=None,
                 scheme='default'):
        if [path, fileobj, mapping].count(None) < 2:
            raise TypeError('path, fileobj and mapping are exclusive')
        self._fields = {}
        self.requires_files = []
        self._dependencies = None
        self.scheme = scheme
        if path is not None:
            self.read(path)
        elif fileobj is not None:
            self.read_file(fileobj)
        elif mapping is not None:
            self.update(mapping)
            self.set_metadata_version()

    def set_metadata_version(self):
        self._fields['Metadata-Version'] = _best_version(self._fields)

    def _write_field(self, fileobj, name, value):
        fileobj.write('%s: %s\n' % (name, value))

    def __getitem__(self, name):
        return self.get(name)

    def __setitem__(self, name, value):
        return self.set(name, value)

    def __delitem__(self, name):
        field_name = self._convert_name(name)
        try:
            del self._fields[field_name]
        except KeyError:
            raise KeyError(name)

    def __contains__(self, name):
        return (name in self._fields or
                self._convert_name(name) in self._fields)

    def _convert_name(self, name):
        if name in _ALL_FIELDS:
            return name
        name = name.replace('-', '_').lower()
        return _ATTR2FIELD.get(name, name)

    def _default_value(self, name):
        if name in _LISTFIELDS or name in _ELEMENTSFIELD:
            return []
        return 'UNKNOWN'

    def _remove_line_prefix(self, value):
        if self.metadata_version in ('1.0', '1.1'):
            return _LINE_PREFIX_PRE_1_2.sub('\n', value)
        else:
            return _LINE_PREFIX_1_2.sub('\n', value)

    def __getattr__(self, name):
        if name in _ATTR2FIELD:
            return self[name]
        raise AttributeError(name)

    #
    # Public API
    #

#    dependencies = property(_get_dependencies, _set_dependencies)

    def get_fullname(self, filesafe=False):
        """Return the distribution name with version.

        If filesafe is true, return a filename-escaped form."""
        return _get_name_and_version(self['Name'], self['Version'], filesafe)

    def is_field(self, name):
        """return True if name is a valid metadata key"""
        name = self._convert_name(name)
        return name in _ALL_FIELDS

    def is_multi_field(self, name):
        name = self._convert_name(name)
        return name in _LISTFIELDS

    def read(self, filepath):
        """Read the metadata values from a file path."""
        fp = codecs.open(filepath, 'r', encoding='utf-8')
        try:
            self.read_file(fp)
        finally:
            fp.close()

    def read_file(self, fileob):
        """Read the metadata values from a file object."""
        msg = message_from_file(fileob)
        self._fields['Metadata-Version'] = msg['metadata-version']

        # When reading, get all the fields we can
        for field in _ALL_FIELDS:
            if field not in msg:
                continue
            if field in _LISTFIELDS:
                # we can have multiple lines
                values = msg.get_all(field)
                if field in _LISTTUPLEFIELDS and values is not None:
                    values = [tuple(value.split(',')) for value in values]
                self.set(field, values)
            else:
                # single line
                value = msg[field]
                if value is not None and value != 'UNKNOWN':
                    self.set(field, value)

        # PEP 566 specifies that the body be used for the description, if
        # available
        body = msg.get_payload()
        self["Description"] = body if body else self["Description"]
        # logger.debug('Attempting to set metadata for %s', self)
        # self.set_metadata_version()

    def write(self, filepath, skip_unknown=False):
        """Write the metadata fields to filepath."""
        fp = codecs.open(filepath, 'w', encoding='utf-8')
        try:
            self.write_file(fp, skip_unknown)
        finally:
            fp.close()

    def write_file(self, fileobject, skip_unknown=False):
        """Write the PKG-INFO format data to a file object."""
        self.set_metadata_version()

        for field in _version2fieldlist(self['Metadata-Version']):
            values = self.get(field)
            if skip_unknown and values in ('UNKNOWN', [], ['UNKNOWN']):
                continue
            if field in _ELEMENTSFIELD:
                self._write_field(fileobject, field, ','.join(values))
                continue
            if field not in _LISTFIELDS:
                if field == 'Description':
                    if self.metadata_version in ('1.0', '1.1'):
                        values = values.replace('\n', '\n        ')
                    else:
                        values = values.replace('\n', '\n       |')
                values = [values]

            if field in _LISTTUPLEFIELDS:
                values = [','.join(value) for value in values]

            for value in values:
                self._write_field(fileobject, field, value)

    def update(self, other=None, **kwargs):
        """Set metadata values from the given iterable `other` and kwargs.

        Behavior is like `dict.update`: If `other` has a ``keys`` method,
        they are looped over and ``self[key]`` is assigned ``other[key]``.
        Else, ``other`` is an iterable of ``(key, value)`` iterables.

        Keys that don't match a metadata field or that have an empty value are
        dropped.
        """
        def _set(key, value):
            if key in _ATTR2FIELD and value:
                self.set(self._convert_name(key), value)

        if not other:
            # other is None or empty container
            pass
        elif hasattr(other, 'keys'):
            for k in other.keys():
                _set(k, other[k])
        else:
            for k, v in other:
                _set(k, v)

        if kwargs:
            for k, v in kwargs.items():
                _set(k, v)

    def set(self, name, value):
        """Control then set a metadata field."""
        name = self._convert_name(name)

        if ((name in _ELEMENTSFIELD or name == 'Platform') and
            not isinstance(value, (list, tuple))):
            if isinstance(value, string_types):
                value = [v.strip() for v in value.split(',')]
            else:
                value = []
        elif (name in _LISTFIELDS and
              not isinstance(value, (list, tuple))):
            if isinstance(value, string_types):
                value = [value]
            else:
                value = []

        if logger.isEnabledFor(logging.WARNING):
            project_name = self['Name']

            scheme = get_scheme(self.scheme)
            if name in _PREDICATE_FIELDS and value is not None:
                for v in value:
                    # check that the values are valid
                    if not scheme.is_valid_matcher(v.split(';')[0]):
                        logger.warning(
                            "'%s': '%s' is not valid (field '%s')",
                            project_name, v, name)
            # FIXME this rejects UNKNOWN, is that right?
            elif name in _VERSIONS_FIELDS and value is not None:
                if not scheme.is_valid_constraint_list(value):
                    logger.warning("'%s': '%s' is not a valid version (field '%s')",
                                   project_name, value, name)
            elif name in _VERSION_FIELDS and value is not None:
                if not scheme.is_valid_version(value):
                    logger.warning("'%s': '%s' is not a valid version (field '%s')",
                                   project_name, value, name)

        if name in _UNICODEFIELDS:
            if name == 'Description':
                value = self._remove_line_prefix(value)

        self._fields[name] = value

    def get(self, name, default=_MISSING):
        """Get a metadata field."""
        name = self._convert_name(name)
        if name not in self._fields:
            if default is _MISSING:
                default = self._default_value(name)
            return default
        if name in _UNICODEFIELDS:
            value = self._fields[name]
            return value
        elif name in _LISTFIELDS:
            value = self._fields[name]
            if value is None:
                return []
            res = []
            for val in value:
                if name not in _LISTTUPLEFIELDS:
                    res.append(val)
                else:
                    # That's for Project-URL
                    res.append((val[0], val[1]))
            return res

        elif name in _ELEMENTSFIELD:
            value = self._fields[name]
            if isinstance(value, string_types):
                return value.split(',')
        return self._fields[name]

    def check(self, strict=False):
        """Check if the metadata is compliant. If strict is True then raise if
        no Name or Version are provided"""
        self.set_metadata_version()

        # XXX should check the versions (if the file was loaded)
        missing, warnings = [], []

        for attr in ('Name', 'Version'):  # required by PEP 345
            if attr not in self:
                missing.append(attr)

        if strict and missing != []:
            msg = 'missing required metadata: %s' % ', '.join(missing)
            raise MetadataMissingError(msg)

        for attr in ('Home-page', 'Author'):
            if attr not in self:
                missing.append(attr)

        # checking metadata 1.2 (XXX needs to check 1.1, 1.0)
        if self['Metadata-Version'] != '1.2':
            return missing, warnings

        scheme = get_scheme(self.scheme)

        def are_valid_constraints(value):
            for v in value:
                if not scheme.is_valid_matcher(v.split(';')[0]):
                    return False
            return True

        for fields, controller in ((_PREDICATE_FIELDS, are_valid_constraints),
                                   (_VERSIONS_FIELDS,
                                    scheme.is_valid_constraint_list),
                                   (_VERSION_FIELDS,
                                    scheme.is_valid_version)):
            for field in fields:
                value = self.get(field, None)
                if value is not None and not controller(value):
                    warnings.append("Wrong value for '%s': %s" % (field, value))

        return missing, warnings

    def todict(self, skip_missing=False):
        """Return fields as a dict.

        Field names will be converted to use the underscore-lowercase style
        instead of hyphen-mixed case (i.e. home_page instead of Home-page).
        This is as per https://www.python.org/dev/peps/pep-0566/#id17.
        """
        self.set_metadata_version()

        fields = _version2fieldlist(self['Metadata-Version'])

        data = {}

        for field_name in fields:
            if not skip_missing or field_name in self._fields:
                key = _FIELD2ATTR[field_name]
                if key != 'project_url':
                    data[key] = self[field_name]
                else:
                    data[key] = [','.join(u) for u in self[field_name]]

        return data

    def add_requirements(self, requirements):
        if self['Metadata-Version'] == '1.1':
            # we can't have 1.1 metadata *and* Setuptools requires
            for field in ('Obsoletes', 'Requires', 'Provides'):
                if field in self:
                    del self[field]
        self['Requires-Dist'] += requirements

    # Mapping API
    # TODO could add iter* variants

    def keys(self):
        return list(_version2fieldlist(self['Metadata-Version']))

    def __iter__(self):
        for key in self.keys():
            yield key

    def values(self):
        return [self[key] for key in self.keys()]

    def items(self):
        return [(key, self[key]) for key in self.keys()]

    def __repr__(self):
        return '<%s %s %s>' % (self.__class__.__name__, self.name,
                               self.version)


METADATA_FILENAME = 'pydist.json'
WHEEL_METADATA_FILENAME = 'metadata.json'
LEGACY_METADATA_FILENAME = 'METADATA'


class Metadata(object):
    """
    The metadata of a release. This implementation uses 2.1
    metadata where possible. If not possible, it wraps a LegacyMetadata
    instance which handles the key-value metadata format.
    """

    METADATA_VERSION_MATCHER = re.compile(r'^\d+(\.\d+)*$')

    NAME_MATCHER = re.compile('^[0-9A-Z]([0-9A-Z_.-]*[0-9A-Z])?$', re.I)

    FIELDNAME_MATCHER = re.compile('^[A-Z]([0-9A-Z-]*[0-9A-Z])?$', re.I)

    VERSION_MATCHER = PEP440_VERSION_RE

    SUMMARY_MATCHER = re.compile('.{1,2047}')

    METADATA_VERSION = '2.0'

    GENERATOR = 'distlib (%s)' % __version__

    MANDATORY_KEYS = {
        'name': (),
        'version': (),
        'summary': ('legacy',),
    }

    INDEX_KEYS = ('name version license summary description author '
                  'author_email keywords platform home_page classifiers '
                  'download_url')

    DEPENDENCY_KEYS = ('extras run_requires test_requires build_requires '
                       'dev_requires provides meta_requires obsoleted_by '
                       'supports_environments')

    SYNTAX_VALIDATORS = {
        'metadata_version': (METADATA_VERSION_MATCHER, ()),
        'name': (NAME_MATCHER, ('legacy',)),
        'version': (VERSION_MATCHER, ('legacy',)),
        'summary': (SUMMARY_MATCHER, ('legacy',)),
        'dynamic': (FIELDNAME_MATCHER, ('legacy',)),
    }

    __slots__ = ('_legacy', '_data', 'scheme')

    def __init__(self, path=None, fileobj=None, mapping=None,
                 scheme='default'):
        if [path, fileobj, mapping].count(None) < 2:
            raise TypeError('path, fileobj and mapping are exclusive')
        self._legacy = None
        self._data = None
        self.scheme = scheme
        #import pdb; pdb.set_trace()
        if mapping is not None:
            try:
                self._validate_mapping(mapping, scheme)
                self._data = mapping
            except MetadataUnrecognizedVersionError:
                self._legacy = LegacyMetadata(mapping=mapping, scheme=scheme)
                self.validate()
        else:
            data = None
            if path:
                with open(path, 'rb') as f:
                    data = f.read()
            elif fileobj:
                data = fileobj.read()
            if data is None:
                # Initialised with no args - to be added
                self._data = {
                    'metadata_version': self.METADATA_VERSION,
                    'generator': self.GENERATOR,
                }
            else:
                if not isinstance(data, text_type):
                    data = data.decode('utf-8')
                try:
                    self._data = json.loads(data)
                    self._validate_mapping(self._data, scheme)
                except ValueError:
                    # Note: MetadataUnrecognizedVersionError does not
                    # inherit from ValueError (it's a DistlibException,
                    # which should not inherit from ValueError).
                    # The ValueError comes from the json.load - if that
                    # succeeds and we get a validation error, we want
                    # that to propagate
                    self._legacy = LegacyMetadata(fileobj=StringIO(data),
                                                  scheme=scheme)
                    self.validate()

    common_keys = set(('name', 'version', 'license', 'keywords', 'summary'))

    none_list = (None, list)
    none_dict = (None, dict)

    mapped_keys = {
        'run_requires': ('Requires-Dist', list),
        'build_requires': ('Setup-Requires-Dist', list),
        'dev_requires': none_list,
        'test_requires': none_list,
        'meta_requires': none_list,
        'extras': ('Provides-Extra', list),
        'modules': none_list,
        'namespaces': none_list,
        'exports': none_dict,
        'commands': none_dict,
        'classifiers': ('Classifier', list),
        'source_url': ('Download-URL', None),
        'metadata_version': ('Metadata-Version', None),
    }

    del none_list, none_dict

    def __getattribute__(self, key):
        common = object.__getattribute__(self, 'common_keys')
        mapped = object.__getattribute__(self, 'mapped_keys')
        if key in mapped:
            lk, maker = mapped[key]
            if self._legacy:
                if lk is None:
                    result = None if maker is None else maker()
                else:
                    result = self._legacy.get(lk)
            else:
                value = None if maker is None else maker()
                if key not in ('commands', 'exports', 'modules', 'namespaces',
                               'classifiers'):
                    result = self._data.get(key, value)
                else:
                    # special cases for PEP 459
                    sentinel = object()
                    result = sentinel
                    d = self._data.get('extensions')
                    if d:
                        if key == 'commands':
                            result = d.get('python.commands', value)
                        elif key == 'classifiers':
                            d = d.get('python.details')
                            if d:
                                result = d.get(key, value)
                        else:
                            d = d.get('python.exports')
                            if not d:
                                d = self._data.get('python.exports')
                            if d:
                                result = d.get(key, value)
                    if result is sentinel:
                        result = value
        elif key not in common:
            result = object.__getattribute__(self, key)
        elif self._legacy:
            result = self._legacy.get(key)
        else:
            result = self._data.get(key)
        return result

    def _validate_value(self, key, value, scheme=None):
        if key in self.SYNTAX_VALIDATORS:
            pattern, exclusions = self.SYNTAX_VALIDATORS[key]
            if (scheme or self.scheme) not in exclusions:
                m = pattern.match(value)
                if not m:
                    raise MetadataInvalidError("'%s' is an invalid value for "
                                               "the '%s' property" % (value,
                                                                    key))

    def __setattr__(self, key, value):
        self._validate_value(key, value)
        common = object.__getattribute__(self, 'common_keys')
        mapped = object.__getattribute__(self, 'mapped_keys')
        if key in mapped:
            lk, _ = mapped[key]
            if self._legacy:
                if lk is None:
                    raise NotImplementedError
                self._legacy[lk] = value
            elif key not in ('commands', 'exports', 'modules', 'namespaces',
                             'classifiers'):
                self._data[key] = value
            else:
                # special cases for PEP 459
                d = self._data.setdefault('extensions', {})
                if key == 'commands':
                    d['python.commands'] = value
                elif key == 'classifiers':
                    d = d.setdefault('python.details', {})
                    d[key] = value
                else:
                    d = d.setdefault('python.exports', {})
                    d[key] = value
        elif key not in common:
            object.__setattr__(self, key, value)
        else:
            if key == 'keywords':
                if isinstance(value, string_types):
                    value = value.strip()
                    if value:
                        value = value.split()
                    else:
                        value = []
            if self._legacy:
                self._legacy[key] = value
            else:
                self._data[key] = value

    @property
    def name_and_version(self):
        return _get_name_and_version(self.name, self.version, True)

    @property
    def provides(self):
        if self._legacy:
            result = self._legacy['Provides-Dist']
        else:
            result = self._data.setdefault('provides', [])
        s = '%s (%s)' % (self.name, self.version)
        if s not in result:
            result.append(s)
        return result

    @provides.setter
    def provides(self, value):
        if self._legacy:
            self._legacy['Provides-Dist'] = value
        else:
            self._data['provides'] = value

    def get_requirements(self, reqts, extras=None, env=None):
        """
        Base method to get dependencies, given a set of extras
        to satisfy and an optional environment context.
        :param reqts: A list of sometimes-wanted dependencies,
                      perhaps dependent on extras and environment.
        :param extras: A list of optional components being requested.
        :param env: An optional environment for marker evaluation.
        """
        if self._legacy:
            result = reqts
        else:
            result = []
            extras = get_extras(extras or [], self.extras)
            for d in reqts:
                if 'extra' not in d and 'environment' not in d:
                    # unconditional
                    include = True
                else:
                    if 'extra' not in d:
                        # Not extra-dependent - only environment-dependent
                        include = True
                    else:
                        include = d.get('extra') in extras
                    if include:
                        # Not excluded because of extras, check environment
                        marker = d.get('environment')
                        if marker:
                            include = interpret(marker, env)
                if include:
                    result.extend(d['requires'])
            for key in ('build', 'dev', 'test'):
                e = ':%s:' % key
                if e in extras:
                    extras.remove(e)
                    # A recursive call, but it should terminate since 'test'
                    # has been removed from the extras
                    reqts = self._data.get('%s_requires' % key, [])
                    result.extend(self.get_requirements(reqts, extras=extras,
                                                        env=env))
        return result

    @property
    def dictionary(self):
        if self._legacy:
            return self._from_legacy()
        return self._data

    @property
    def dependencies(self):
        if self._legacy:
            raise NotImplementedError
        else:
            return extract_by_key(self._data, self.DEPENDENCY_KEYS)

    @dependencies.setter
    def dependencies(self, value):
        if self._legacy:
            raise NotImplementedError
        else:
            self._data.update(value)

    def _validate_mapping(self, mapping, scheme):
        if mapping.get('metadata_version') != self.METADATA_VERSION:
            raise MetadataUnrecognizedVersionError()
        missing = []
        for key, exclusions in self.MANDATORY_KEYS.items():
            if key not in mapping:
                if scheme not in exclusions:
                    missing.append(key)
        if missing:
            msg = 'Missing metadata items: %s' % ', '.join(missing)
            raise MetadataMissingError(msg)
        for k, v in mapping.items():
            self._validate_value(k, v, scheme)

    def validate(self):
        if self._legacy:
            missing, warnings = self._legacy.check(True)
            if missing or warnings:
                logger.warning('Metadata: missing: %s, warnings: %s',
                               missing, warnings)
        else:
            self._validate_mapping(self._data, self.scheme)

    def todict(self):
        if self._legacy:
            return self._legacy.todict(True)
        else:
            result = extract_by_key(self._data, self.INDEX_KEYS)
            return result

    def _from_legacy(self):
        assert self._legacy and not self._data
        result = {
            'metadata_version': self.METADATA_VERSION,
            'generator': self.GENERATOR,
        }
        lmd = self._legacy.todict(True)     # skip missing ones
        for k in ('name', 'version', 'license', 'summary', 'description',
                  'classifier'):
            if k in lmd:
                if k == 'classifier':
                    nk = 'classifiers'
                else:
                    nk = k
                result[nk] = lmd[k]
        kw = lmd.get('Keywords', [])
        if kw == ['']:
            kw = []
        result['keywords'] = kw
        keys = (('requires_dist', 'run_requires'),
                ('setup_requires_dist', 'build_requires'))
        for ok, nk in keys:
            if ok in lmd and lmd[ok]:
                result[nk] = [{'requires': lmd[ok]}]
        result['provides'] = self.provides
        author = {}
        maintainer = {}
        return result

    LEGACY_MAPPING = {
        'name': 'Name',
        'version': 'Version',
        ('extensions', 'python.details', 'license'): 'License',
        'summary': 'Summary',
        'description': 'Description',
        ('extensions', 'python.project', 'project_urls', 'Home'): 'Home-page',
        ('extensions', 'python.project', 'contacts', 0, 'name'): 'Author',
        ('extensions', 'python.project', 'contacts', 0, 'email'): 'Author-email',
        'source_url': 'Download-URL',
        ('extensions', 'python.details', 'classifiers'): 'Classifier',
    }

    def _to_legacy(self):
        def process_entries(entries):
            reqts = set()
            for e in entries:
                extra = e.get('extra')
                env = e.get('environment')
                rlist = e['requires']
                for r in rlist:
                    if not env and not extra:
                        reqts.add(r)
                    else:
                        marker = ''
                        if extra:
                            marker = 'extra == "%s"' % extra
                        if env:
                            if marker:
                                marker = '(%s) and %s' % (env, marker)
                            else:
                                marker = env
                        reqts.add(';'.join((r, marker)))
            return reqts

        assert self._data and not self._legacy
        result = LegacyMetadata()
        nmd = self._data
        # import pdb; pdb.set_trace()
        for nk, ok in self.LEGACY_MAPPING.items():
            if not isinstance(nk, tuple):
                if nk in nmd:
                    result[ok] = nmd[nk]
            else:
                d = nmd
                found = True
                for k in nk:
                    try:
                        d = d[k]
                    except (KeyError, IndexError):
                        found = False
                        break
                if found:
                    result[ok] = d
        r1 = process_entries(self.run_requires + self.meta_requires)
        r2 = process_entries(self.build_requires + self.dev_requires)
        if self.extras:
            result['Provides-Extra'] = sorted(self.extras)
        result['Requires-Dist'] = sorted(r1)
        result['Setup-Requires-Dist'] = sorted(r2)
        # TODO: any other fields wanted
        return result

    def write(self, path=None, fileobj=None, legacy=False, skip_unknown=True):
        if [path, fileobj].count(None) != 1:
            raise ValueError('Exactly one of path and fileobj is needed')
        self.validate()
        if legacy:
            if self._legacy:
                legacy_md = self._legacy
            else:
                legacy_md = self._to_legacy()
            if path:
                legacy_md.write(path, skip_unknown=skip_unknown)
            else:
                legacy_md.write_file(fileobj, skip_unknown=skip_unknown)
        else:
            if self._legacy:
                d = self._from_legacy()
            else:
                d = self._data
            if fileobj:
                json.dump(d, fileobj, ensure_ascii=True, indent=2,
                          sort_keys=True)
            else:
                with codecs.open(path, 'w', 'utf-8') as f:
                    json.dump(d, f, ensure_ascii=True, indent=2,
                              sort_keys=True)

    def add_requirements(self, requirements):
        if self._legacy:
            self._legacy.add_requirements(requirements)
        else:
            run_requires = self._data.setdefault('run_requires', [])
            always = None
            for entry in run_requires:
                if 'environment' not in entry and 'extra' not in entry:
                    always = entry
                    break
            if always is None:
                always = { 'requires': requirements }
                run_requires.insert(0, always)
            else:
                rset = set(always['requires']) | set(requirements)
                always['requires'] = sorted(rset)

    def __repr__(self):
        name = self.name or '(no name)'
        version = self.version or 'no version'
        return '<%s %s %s (%s)>' % (self.__class__.__name__,
                                    self.metadata_version, name, version)
¿Qué es la limpieza dental de perros? - Clínica veterinaria


Es la eliminación del sarro y la placa adherida a la superficie de los dientes mediante un equipo de ultrasonidos que garantiza la integridad de las piezas dentales a la vez que elimina en profundidad cualquier resto de suciedad.

A continuación se procede al pulido de los dientes mediante una fresa especial que elimina la placa bacteriana y devuelve a los dientes el aspecto sano que deben tener.

Una vez terminado todo el proceso, se mantiene al perro en observación hasta que se despierta de la anestesia, bajo la atenta supervisión de un veterinario.

¿Cada cuánto tiempo tengo que hacerle una limpieza dental a mi perro?

A partir de cierta edad, los perros pueden necesitar una limpieza dental anual o bianual. Depende de cada caso. En líneas generales, puede decirse que los perros de razas pequeñas suelen acumular más sarro y suelen necesitar una atención mayor en cuanto a higiene dental.


Riesgos de una mala higiene


Los riesgos más evidentes de una mala higiene dental en los perros son los siguientes:

  • Cuando la acumulación de sarro no se trata, se puede producir una inflamación y retracción de las encías que puede descalzar el diente y provocar caídas.
  • Mal aliento (halitosis).
  • Sarro perros
  • Puede ir a más
  • Las bacterias de la placa pueden trasladarse a través del torrente circulatorio a órganos vitales como el corazón ocasionando problemas de endocarditis en las válvulas. Las bacterias pueden incluso acantonarse en huesos (La osteomielitis es la infección ósea, tanto cortical como medular) provocando mucho dolor y una artritis séptica).

¿Cómo se forma el sarro?

El sarro es la calcificación de la placa dental. Los restos de alimentos, junto con las bacterias presentes en la boca, van a formar la placa bacteriana o placa dental. Si la placa no se retira, al mezclarse con la saliva y los minerales presentes en ella, reaccionará formando una costra. La placa se calcifica y se forma el sarro.

El sarro, cuando se forma, es de color blanquecino pero a medida que pasa el tiempo se va poniendo amarillo y luego marrón.

Síntomas de una pobre higiene dental
La señal más obvia de una mala salud dental canina es el mal aliento.

Sin embargo, a veces no es tan fácil de detectar
Y hay perros que no se dejan abrir la boca por su dueño. Por ejemplo…

Recientemente nos trajeron a la clínica a un perro que parpadeaba de un ojo y decía su dueño que le picaba un lado de la cara. Tenía molestias y dificultad para comer, lo que había llevado a sus dueños a comprarle comida blanda (que suele ser un poco más cara y llevar más contenido en grasa) durante medio año. Después de una exploración oftalmológica, nos dimos cuenta de que el ojo tenía una úlcera en la córnea probablemente de rascarse . Además, el canto lateral del ojo estaba inflamado. Tenía lo que en humanos llamamos flemón pero como era un perro de pelo largo, no se le notaba a simple vista. Al abrirle la boca nos llamó la atención el ver una muela llena de sarro. Le realizamos una radiografía y encontramos una fístula que llegaba hasta la parte inferior del ojo.

Le tuvimos que extraer la muela. Tras esto, el ojo se curó completamente con unos colirios y una lentilla protectora de úlcera. Afortunadamente, la úlcera no profundizó y no perforó el ojo. Ahora el perro come perfectamente a pesar de haber perdido una muela.

¿Cómo mantener la higiene dental de tu perro?
Hay varias maneras de prevenir problemas derivados de la salud dental de tu perro.

Limpiezas de dientes en casa
Es recomendable limpiar los dientes de tu perro semanal o diariamente si se puede. Existe una gran variedad de productos que se pueden utilizar:

Pastas de dientes.
Cepillos de dientes o dedales para el dedo índice, que hacen más fácil la limpieza.
Colutorios para echar en agua de bebida o directamente sobre el diente en líquido o en spray.

En la Clínica Tus Veterinarios enseñamos a nuestros clientes a tomar el hábito de limpiar los dientes de sus perros desde que son cachorros. Esto responde a nuestro compromiso con la prevención de enfermedades caninas.

Hoy en día tenemos muchos clientes que limpian los dientes todos los días a su mascota, y como resultado, se ahorran el dinero de hacer limpiezas dentales profesionales y consiguen una mejor salud de su perro.


Limpiezas dentales profesionales de perros y gatos

Recomendamos hacer una limpieza dental especializada anualmente. La realizamos con un aparato de ultrasonidos que utiliza agua para quitar el sarro. Después, procedemos a pulir los dientes con un cepillo de alta velocidad y una pasta especial. Hacemos esto para proteger el esmalte.

La frecuencia de limpiezas dentales necesaria varía mucho entre razas. En general, las razas grandes tienen buena calidad de esmalte, por lo que no necesitan hacerlo tan a menudo e incluso pueden pasarse la vida sin requerir una limpieza. Sin embargo, razas pequeñas como el Yorkshire o el Maltés, deben hacérselas todos los años desde cachorros si se quiere conservar sus piezas dentales.

Otro factor fundamental es la calidad del pienso. Algunas marcas han diseñado croquetas que limpian la superficie del diente y de la muela al masticarse.

Ultrasonido para perros

¿Se necesita anestesia para las limpiezas dentales de perros y gatos?

La limpieza dental en perros no es una técnica que pueda practicarse sin anestesia general , aunque hay veces que los propietarios no quieren anestesiar y si tiene poco sarro y el perro es muy bueno se puede intentar…… , pero no se va a poder pulir ni acceder a todas la zona de la boca …. Además los limpiadores dentales van a irrigar agua y hay riesgo de aspiración a vías respiratorias si no se realiza una anestesia correcta con intubación traqueal . En resumen , sin anestesia no se va hacer una correcta limpieza dental.

Tampoco sirve la sedación ya que necesitamos que el animal esté totalmente quieto, y el veterinario tenga un acceso completo a todas sus piezas dentales y encías.

Alimentos para la limpieza dental

Hay que tener cierto cuidado a la hora de comprar determinados alimentos porque no todos son saludables. Algunos tienen demasiado contenido graso, que en exceso puede causar problemas cardiovasculares y obesidad.

Los mejores alimentos para los dientes son aquellos que están elaborados por empresas farmacéuticas y llevan componentes químicos con tratamientos específicos para el diente del perro. Esto implica no solo limpieza a través de la acción mecánica de morder sino también un tratamiento antibacteriano para prevenir el sarro.

Conclusión

Si eres como la mayoría de dueños, por falta de tiempo , es probable que no estés prestando la suficiente atención a la limpieza dental de tu perro. Por eso te animamos a que comiences a limpiar los dientes de tu perro y consideres atender a su higiene bucal con frecuencia.

Estas simples medidas pueden conllevar a que tu perro tenga una vida más larga y mucho más saludable.

Si te resulta imposible introducir un cepillo de dientes a tu perro en la boca, pásate con él por clínica Tus Veterinarios y te explicamos cómo hacerlo.

Necesitas hacer una limpieza dental profesional a tu mascota?
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