"""Coordinate sequence utilities."""
from array import array
class CoordinateSequence:
"""Access to coordinate tuples from the parent geometry's coordinate sequence.
Examples
--------
>>> from shapely.wkt import loads
>>> g = loads('POINT (0.0 0.0)')
>>> list(g.coords)
[(0.0, 0.0)]
>>> g = loads('POINT M (1 2 4)')
>>> g.coords[:]
[(1.0, 2.0, 4.0)]
"""
def __init__(self, coords):
"""Initialize the CoordinateSequence.
Parameters
----------
coords : array
The coordinate array.
"""
self._coords = coords
def __len__(self):
"""Return the length of the CoordinateSequence.
Returns
-------
int
The length of the CoordinateSequence.
"""
return self._coords.shape[0]
def __iter__(self):
"""Iterate over the CoordinateSequence."""
for i in range(self.__len__()):
yield tuple(self._coords[i].tolist())
def __getitem__(self, key):
"""Get the item at the specified index or slice.
Parameters
----------
key : int or slice
The index or slice.
Returns
-------
tuple or list
The item at the specified index or slice.
"""
m = self.__len__()
if isinstance(key, int):
if key + m < 0 or key >= m:
raise IndexError("index out of range")
if key < 0:
i = m + key
else:
i = key
return tuple(self._coords[i].tolist())
elif isinstance(key, slice):
res = []
start, stop, stride = key.indices(m)
for i in range(start, stop, stride):
res.append(tuple(self._coords[i].tolist()))
return res
else:
raise TypeError("key must be an index or slice")
def __array__(self, dtype=None, copy=None):
"""Return a copy of the coordinate array.
Parameters
----------
dtype : data-type, optional
The desired data-type for the array.
copy : bool, optional
If None (default) or True, a copy of the array is always returned.
If False, a ValueError is raised as this is not supported.
Returns
-------
array
The coordinate array.
Raises
------
ValueError
If `copy=False` is specified.
"""
if copy is False:
raise ValueError("`copy=False` isn't supported. A copy is always created.")
elif copy is True:
return self._coords.copy()
else:
return self._coords
@property
def xy(self):
"""X and Y arrays."""
m = self.__len__()
x = array("d")
y = array("d")
for i in range(m):
xy = self._coords[i].tolist()
x.append(xy[0])
y.append(xy[1])
return x, y