Source code for openpyxl.descriptors.sequence

# copyright openpyxl 2010-2015

from openpyxl.compat import safe_string
from openpyxl.xml.functions import Element
from openpyxl.utils.indexed_list import IndexedList

from .base import Descriptor, Alias, _convert
from .namespace import namespaced


[docs]class Sequence(Descriptor): """ A sequence (list or tuple) that may only contain objects of the declared type """ expected_type = type(None) seq_types = (list, tuple) idx_base = 0 unique = False def __set__(self, instance, seq): if not isinstance(seq, self.seq_types): raise TypeError("Value must be a sequence") seq = [_convert(self.expected_type, value) for value in seq] if self.unique: seq = IndexedList(seq) super(Sequence, self).__set__(instance, seq)
[docs] def to_tree(self, tagname, obj, namespace=None): """ Convert the sequence represented by the descriptor to an XML element """ for idx, v in enumerate(obj, self.idx_base): if hasattr(v, "to_tree"): el = v.to_tree(tagname, idx) else: tagname = namespaced(obj, tagname, namespace) el = Element(tagname) el.text = safe_string(v) yield el
[docs]class ValueSequence(Sequence): """ A sequence of primitive types that are stored as a single attribute. "val" is the default attribute """ attribute = "val"
[docs] def to_tree(self, tagname, obj, namespace=None): tagname = namespaced(self, tagname, namespace) for v in obj: yield Element(tagname, {self.attribute:safe_string(v)})
[docs] def from_tree(self, node): return node.get(self.attribute)
[docs]class NestedSequence(Sequence): """ Wrap a sequence in an containing object """ count = False
[docs] def to_tree(self, tagname, obj, namespace=None): tagname = namespaced(self, tagname, namespace) container = Element(tagname) if self.count: container.set('count', str(len(obj))) for v in obj: container.append(v.to_tree()) return container
[docs] def from_tree(self, node): return [self.expected_type.from_tree(el) for el in node]
[docs]class MultiSequence(Sequence): """ Sequences can contain objects with different tags """ def __set__(self, instance, seq): if not isinstance(seq, (tuple, list)): raise ValueError("Value must be a sequence") seq = list(seq) Descriptor.__set__(self, instance, seq)
[docs] def to_tree(self, tagname, obj, namespace=None): """ Convert the sequence represented by the descriptor to an XML element """ for v in obj: el = v.to_tree(namespace=namespace) yield el
[docs]class MultiSequencePart(Alias): """ Allow a multisequence to be built up from parts Excluded from the instance __elements__ or __attrs__ as is effectively an Alias """ def __init__(self, expected_type, store): self.expected_type = expected_type self.store = store def __set__(self, instance, value): value = _convert(self.expected_type, value) instance.__dict__[self.store].append(value) def __get__(self, instance, cls): return self