Source code for cobra.core.DictList

import re
from itertools import islice
from six import string_types, iteritems, PY3

try:
    from numpy import bool_
except:
    bool_ = bool


[docs]class DictList(list): """A combined dict and list This object behaves like a list, but has the O(1) speed benefits of a dict when looking up elements by their id. """ def __init__(self, *args): if len(args) > 2: raise TypeError("takes at most 1 argument (%d given)" % len(args)) list.__init__(self) self._dict = {} if len(args) == 1: other = args[0] if isinstance(other, DictList): list.extend(self, other) self._dict = other._dict.copy() else: self.extend(other)
[docs] def has_id(self, id): return id in self._dict
def _check(self, id): """make sure duplicate id's are not added. This function is called before adding in elements. """ if id in self._dict: raise ValueError("id %s is already present in list" % str(id)) def _generate_index(self): """rebuild the _dict index""" self._dict = {v.id: k for k, v in enumerate(self)}
[docs] def get_by_id(self, id): """return the element with a matching id""" return list.__getitem__(self, self._dict[id])
[docs] def list_attr(self, attribute): """return a list of the given attribute for every object """ return [getattr(i, attribute) for i in self]
[docs] def query(self, search_function, attribute="id"): """query the list search_function: used to select which objects to return * a string, in which case any object.attribute containing the string will be returned * a compiled regular expression * a function which takes one argument and returns True for desired values attribute: the attribute to be searched for (default is 'id'). If this is None, the object itself is used. returns: a list of objects which match the query """ if attribute is None: def select_attribute(x): return x else: def select_attribute(x): return getattr(x, attribute) # if the search_function is a regular expression if isinstance(search_function, string_types): search_function = re.compile(search_function) if hasattr(search_function, "findall"): matches = (i for i in self if search_function.findall(select_attribute(i)) != []) else: matches = (i for i in self if search_function(select_attribute(i))) results = self.__class__() results._extend_nocheck(matches) return results
def _replace_on_id(self, new_object): """Replace an object by another with the same id.""" the_id = new_object.id the_index = self._dict[the_id] list.__setitem__(self, the_index, new_object) # overriding default list functions with new ones
[docs] def append(self, object): """append object to end""" the_id = object.id self._check(the_id) self._dict[the_id] = len(self) list.append(self, object)
[docs] def union(self, iterable): """adds elements with id's not already in the model""" _dict = self._dict append = self.append for i in iterable: if i.id not in _dict: append(i)
[docs] def extend(self, iterable): """extend list by appending elements from the iterable""" # Sometimes during initialization from an older pickle, _dict # will not have initialized yet, because the initialization class was # left unspecified. This is an issue because unpickling calls # DictList.extend, which requires the presence of _dict. Therefore, # the issue is caught and addressed here. if not hasattr(self, "_dict") or self._dict is None: self._dict = {} _dict = self._dict current_length = len(self) list.extend(self, iterable) for i, obj in enumerate(islice(self, current_length, None), current_length): the_id = obj.id if the_id not in _dict: _dict[the_id] = i else: # undo the extend and raise an error self = self[:current_length] self._check(the_id) # if the above succeeded, then the id must be present # twice in the list being added raise ValueError("id '%s' at index %d is non-unique. " "Is it present twice?" % (str(the_id), i))
def _extend_nocheck(self, iterable): """extends without checking for uniqueness This function should only be used internally by DictList when it can guarentee elements are already unique (as in when coming from self or other DictList). It will be faster because it skips these checks. """ current_length = len(self) list.extend(self, iterable) _dict = self._dict if current_length is 0: self._generate_index() return for i, obj in enumerate(islice(self, current_length, None), current_length): _dict[obj.id] = i
[docs] def __add__(self, other): """x.__add__(y) <==> x + y other: iterable other must contain only unique id's which do not intersect with self """ total = DictList() total.extend(self) total.extend(other) return total
[docs] def __iadd__(self, other): """x.__iadd__(y) <==> x += y other: iterable other must contain only unique id's whcih do not intersect with self """ self.extend(other) return self
def __reduce__(self): return (self.__class__, (), self.__getstate__(), self.__iter__())
[docs] def __getstate__(self): """gets internal state This is only provided for backwards compatibilty so older versions of cobrapy can load pickles generated with cobrapy. In reality, the "_dict" state is ignored when loading a pickle""" return {"_dict": self._dict}
[docs] def __setstate__(self, state): """sets internal state Ignore the passed in state and recalculate it. This is only for compatibility with older pickles which did not correctly specify the initialization class""" self._generate_index()
[docs] def index(self, id, *args): """Determine the position in the list id: A string or a :class:`~cobra.core.Object.Object` """ # because values are unique, start and stop are not relevant if isinstance(id, string_types): try: return self._dict[id] except KeyError: raise ValueError("%s not found" % id) try: i = self._dict[id.id] if self[i] is not id: raise ValueError( "Another object with the identical id (%s) found" % id.id) return i except KeyError: raise ValueError("%s not found" % str(id))
[docs] def __contains__(self, object): """DictList.__contains__(object) <==> object in DictList object: str or :class:`~cobra.core.Object.Object` """ if hasattr(object, "id"): the_id = object.id # allow to check with the object itself in addition to the id else: the_id = object return the_id in self._dict
def __copy__(self): the_copy = DictList() list.extend(the_copy, self) the_copy._dict = self._dict.copy() return the_copy
[docs] def insert(self, index, object): """insert object before index""" self._check(object.id) list.insert(self, index, object) # all subsequent entries now have been shifted up by 1 _dict = self._dict for i, j in iteritems(_dict): if j >= index: _dict[i] = j + 1 _dict[object.id] = index
[docs] def pop(self, *args): """remove and return item at index (default last).""" value = list.pop(self, *args) index = self._dict.pop(value.id) # If the pop occured from a location other than the end of the list, # we will need to subtract 1 from every entry afterwards if len(args) == 0 or args == [-1]: # removing from the end of the list return value _dict = self._dict for i, j in iteritems(_dict): if j > index: _dict[i] = j - 1 return value
[docs] def remove(self, x): """.. warning :: Internal use only""" # Each item is unique in the list which allows this # It is much faster to do a dict lookup than n string comparisons self.pop(self.index(x))
# these functions are slower because they rebuild the _dict every time
[docs] def reverse(self): """reverse *IN PLACE*""" list.reverse(self) self._generate_index()
[docs] def sort(self, cmp=None, key=None, reverse=False): """stable sort *IN PLACE* cmp(x, y) -> -1, 0, 1 """ if key is None: def key(i): return i.id if PY3: list.sort(self, key=key, reverse=reverse) else: list.sort(self, cmp=cmp, key=key, reverse=reverse) self._generate_index()
def __getitem__(self, i): if isinstance(i, int): return list.__getitem__(self, i) elif isinstance(i, slice): selection = self.__class__() selection._extend_nocheck(list.__getitem__(self, i)) return selection elif hasattr(i, "__len__"): if len(i) == len(self) and isinstance(i[0], (bool, bool_)): selection = self.__class__() result = (o for j, o in enumerate(self) if i[j]) selection._extend_nocheck(result) return selection else: return self.__class__(list.__getitem__(self, i)) else: return list.__getitem__(self, i) def __setitem__(self, i, y): if isinstance(i, slice): # In this case, y needs to be a list. We will ensure all # the id's are unique for obj in y: # need to be setting to a list self._check(obj.id) # Insert a temporary placeholder so we catch the presence # of a duplicate in the items being added self._dict[obj.id] = None list.__setitem__(self, i, y) self._generate_index() return # in case a rename has occured if self._dict.get(self[i].id) == i: self._dict.pop(self[i].id) the_id = y.id self._check(the_id) list.__setitem__(self, i, y) self._dict[the_id] = i def __delitem__(self, index): removed = self[index] list.__delitem__(self, index) if isinstance(removed, list): self._generate_index() return _dict = self._dict _dict.pop(removed.id) for i, j in iteritems(_dict): if j > index: _dict[i] = j - 1 def __getslice__(self, i, j): return self.__getitem__(slice(i, j)) def __setslice__(self, i, j, y): self.__setitem__(slice(i, j), y) def __delslice__(self, i, j): self.__delitem__(slice(i, j)) def __getattr__(self, attr): try: return DictList.get_by_id(self, attr) except KeyError: raise AttributeError("DictList has no attribute or entry %s" % (attr)) def __dir__(self): # override this to allow tab complete of items by their id attributes = dir(self.__class__) attributes.append("_dict") attributes.extend(self._dict.keys()) return attributes