def complement(self, item):
"""Returns complement of item, using data from self.Complements.
Always tries to return same type as item: if item looks like a dict,
will return list of keys.
"""
if not self.Complements:
raise TypeError, "Tried to complement sequence using alphabet without complements."
try:
return item.translate(self.ComplementTable)
except (AttributeError, TypeError):
item = iterable(item)
get = self.Complements.get
return item.__class__([get(i, i) for i in item])
def __init__(self, Spans=[]):
"""Returns a new Range object with data in Spans.
"""
result = SpansOnly()
#need to check if we got a single Span, since they define __iter__.
if isinstance(Spans, Span):
result.append(Spans)
elif hasattr(Spans, 'Spans'): #probably a single range object?
result.extend(Spans.Spans)
else:
for s in iterable(Spans):
if hasattr(s, 'Spans'):
result.extend(s.Spans)
else:
result.append(s)
self.Spans = result
def list_extender(obj, field, val):
"""Adds val to list in obj.field, creating list if necessary."""
try:
getattr(obj, field).extend(iterable(val))
except AttributeError:
setattr(obj, field, list(val))