ABX/abx/ranks.py

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# ranks.py
"""
Branches and ranks objects.
Objects for representing the ranks of a hierarchy, with the
possibility of branching at nodes with redefined ranks via
the 'project_schema' directives in project YAML files.
"""
import numbers
class Branch(object):
"""
Branch represents a ranking system in the tree of schemas.
It takes the name of the project_unit where the ranking system
is overridden, and controls how all ranks defined within it
are interpreted.
"""
def __init__(self, parent, code, start, ranks):
self.parent = parent
self.code = str(code)
self.start = int(start)
self._ranks = RankList(self,[])
if parent:
for rank in parent.ranks:
if int(rank) < start:
self._ranks.append(rank)
for num, name in enumerate(ranks):
rank = Rank(self, num + start, name)
self._ranks.append(rank)
def __repr__(self):
ranklist = ', '.join([str(r) for r in self.ranks[1:]])
if self.code:
code = self.code
else:
code = 'trunk'
return "<branch '%s': %s>" % (code, ranklist)
def __contains__(self, other):
if isinstance(other, Rank) and other in self._ranks:
return True
else:
return False
def rank(self, n):
"""
Coerce int or string to rank, if it matches a rank in this Branch.
"""
if isinstance(n, int) and 0 < n < len(self._ranks):
return self._ranks[n]
elif isinstance(n, str):
for rank in self._ranks:
if str(rank) == n:
return rank
else:
raise TypeError
@property
def ranks(self):
# Read-only property.
return self._ranks
class Rank(object):
"""
Ranks are named numbers indicating the position in a hierarchy.
They can be incremented and decremented. The value 0 represents the top
rank, with increasing numbers indicating finer grades in taxonomic rank.
They can have integers added to or subtracted from them, meaning to go
down or up in rank. They cannot be added to each other, though. Note that
higher and lower rank in the real world since of more or less scope is
inverted as a number -- the lower rank has a higher number.
There are upper and lower bounds to rank, defined by the schema 'Branch'.
Coercing a rank to an integer (int()) returns the numeric rank.
Coercing a rank to a string (str()) returns the rank name.
The representation includes the branch name and rank name.
Ranks can be subtracted, returning an integer representing the difference
in rank.
"""
def __init__(self, branch, num, name):
self.num = num
self.name = name
self.branch = branch
def __index__(self):
return self.num
def __int__(self):
return self.num
def __str__(self):
return self.name
def __repr__(self):
return '<%s:%d-%s>' % (self.branch.code, self.num, self.name)
def __hash__(self):
return hash((self.branch, self.num, self.name))
def __eq__(self, other):
if isinstance(other, Rank):
if hash(self) == hash(other):
return True
else:
return False
elif isinstance(other, str):
if other == self.name:
return True
else:
return False
elif isinstance(other, int):
if other == self.num:
return True
else:
return False
else:
return False
def __gt__(self, other):
if isinstance(other, Rank):
if self.num > other.num:
return True
else:
return False
elif isinstance(other, int):
if self.num > other:
return True
else:
return False
else:
raise TypeError("Rank can't compare to %s" % type(other))
def __lt__(self, other):
if isinstance(other, Rank):
if self.num < other.num:
return True
else:
return False
elif isinstance(other, int):
if self.num < other:
return True
else:
return False
else:
raise TypeError("Rank can't compare to %s" % type(other))
def __ge__(self, other):
return (self > other or self == other)
def __le__(self, other):
return (self < other or self == other)
def __add__(self, other):
if isinstance(other, int):
if (self.num + other) < len(self.branch.ranks):
return self.branch.ranks[self.num+other]
elif (self.num + other) < 1:
return trunk
else:
return None
else:
raise TypeError("Changes in rank must be integers.")
def __radd__(self, other):
return self.__add__(other)
def __sub__(self, other):
if isinstance(other, Rank):
return (self.num - other.num)
elif isinstance(other, int):
if 0 < (self.num - other) < len(self.branch.ranks):
return self.branch.ranks[self.num-other]
elif (self.num - other) < 1:
return trunk
elif (self.num - other) > len(self.branch.ranks):
return None
else:
raise TypeError("Rank subtraction not defined for %s" % type(other))
def __rsub__(self, other):
if isinstance(other, Rank):
return (other.num - self.num)
else:
raise TypeError("Rank subtraction not defined for %s" % type(other))
class RankList(list):
"""
Convenience wrapper for a list of ranks, with simplified look-up.
This allows indexes and slices on the ranks to use Rank objects and/or
string names in addition to integers for accessing the elements of the
list.
The RankList also has to know what branch it is indexing, so it includes
a 'branch' attribute.
"""
def __init__(self, branch, ranks):
self.branch = branch
for rank in ranks:
self.append(rank)
def __getitem__(self, rank):
if isinstance(rank, Rank):
i = int(rank)
elif isinstance(rank, str):
i = [r.name for r in self].index(rank)
elif isinstance(rank, int):
i = rank
elif isinstance(rank, slice):
if rank.start is None:
j = 0
else:
j = self.__getitem__(rank.start)
if rank.stop is None:
k = len(self)
else:
k = self.__getitem__(rank.stop)
s = []
for i in range(j,k):
s.append(super().__getitem__(i))
return s
else:
raise IndexError("Type %s not a valid index for RankList" % type(rank))
return super().__getitem__(i)
# Define the trunk branch object
# This schema will make sense for any unaffiliated Blender document,
# even if it hasn't been saved as a file yet:
trunk = Branch(None, '', 0, ('', 'file', 'scene'))