def __new__(cls,
table_path: str,
field,
where_clause: _tp.Union[None, str, _q.Where] = None):
# Populate the frozenset
with _cursors.SearchCursor(table_path, field, where_clause) as rows:
return super(ValueSet, cls).__new__(cls,
(value for value, in rows))
def _populate(self, table_path, fields, where_clause=None, **kwargs):
""" Populates the lookup with data, calling _process_row() on each row returned by the SearchCursor. """
try:
# Validate fields
self._check_fields(fields, self._get_fields(table_path))
# Validate row processor function (if any)
row_func = kwargs.get(_ROWFUNC_ARG, self._process_row)
has_self = self._has_self(row_func)
with _cursors.SearchCursor(table_path, fields, where_clause) as rows:
for row in rows:
failed = row_func(row, **kwargs) if has_self else row_func(self, row, **kwargs)
if failed:
raise Exception(failed)
except Exception as e:
raise RuntimeError('Failed to create {} for {}: {}'.format(self.__class__.__name__,
_tu.to_repr(table_path), e))
def _populate(self, fc_path, where_clause, all_vertices):
""" Populates the NodeSet with node keys. """
field, all_vertices = self._fix_params(fc_path, all_vertices)
# Iterate over all geometries and add keys
with _cursors.SearchCursor(fc_path, field, where_clause) as rows:
for shape, in rows:
# If the geometry is a simple coordinate tuple, immediately add it
if field.startswith(_const.FIELD_XY):
self.add(get_nodekey(*shape))
continue
if all_vertices:
for coord in _geo.get_vertices(shape):
self.add(get_nodekey(*coord))
continue
# When *all_vertices* is False (or the geometry is not a Multipoint), only get the start/end nodes
self.add(get_nodekey(shape.firstPoint))
self.add(get_nodekey(shape.lastPoint))
def num_rows(self,
where_clause: _tp.Union[str, _q.Where, None] = None) -> int:
"""
Returns the number of rows for a table or feature class.
If the current ``Describe`` object does not support this action or does not have any rows, 0 will be returned.
:param where_clause: An optional where clause to base the row count on.
:type where_clause: str, gpf.tools.queries.Where
"""
field = None
if where_clause:
if isinstance(where_clause, str):
field = _tu.unquote(where_clause.split()[0])
elif hasattr(where_clause, 'fields'):
field = where_clause.fields[0]
else:
raise ValueError(
'where_clause must be a string or Where instance')
try:
if field:
# Iterate over the dataset rows, using the (first) field from the where_clause
with _cursors.SearchCursor(self.catalogPath,
field,
where_clause=where_clause) as rows:
num_rows = sum(1 for _ in rows)
del rows
else:
# Use the ArcPy GetCount() tool for the row count
num_rows = int(
_arcpy.GetCount_management(self.catalogPath).getOutput(0))
except Exception as e:
_warn(str(e), DescribeWarning)
num_rows = 0
return num_rows