Geometry ... ArcPy and NumPy... # 2

DanPatterson_Retired

Part 2... Deconstructing Geometry

•  target="_self">---- Getting Geometry from FeatureClasses ----
• ---- The SearchCursor Approach ----
• ---- The FeatureClassToNumPyArray Approach ----
• ---- Retrieving shape objects ----
• ---- Geometry as a structured array ----
• Helper functions
• _getSR .... spatial reference for a featureclass
• Other links

---- On to the examples ----

The polygons that I will be using are shown to the right.

1. A square, 5 points, first and last duplicates
2. Donut with a Timbit inside
3. A multipart with a donut hole in each
4. The letter 'C'
5. The letter 'V'

Each part is labelled at the labelpoint rather than the centroid, hence each part gets labelled.

‍‍‍

‍‍‍

 

I will be omitting examples that rely on json representation or the __geo_interface__ method since they don't add much to the functionality of constructing and deconstructing poly* type features.

---- Getting Geometry from FeatureClasses ----
---- The SearchCursor Approach ---- The functions getSR and _view_ are described at the end.  They are helper functions used to derive the spatial reference and to reshape the coordinates.  The key operative in this approach is on line 8, _as_narray, which does the conversion behind the scenes. <SPAN class="keyword token">def</SPAN> <SPAN class="token function">cur_xy</SPAN><SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">,</SPAN> to_pnts<SPAN class="operator token">=</SPAN><SPAN class="token boolean">True</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"""Convert featureclass geometry (in_fc) to a simple 2D structured array with ID, X, Y values. Optionally convert to points, otherwise centroid. """</SPAN> SR <SPAN class="operator token">=</SPAN> getSR<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">)</SPAN> flds <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SHAPE@X'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SHAPE@Y'</SPAN><SPAN class="punctuation token">]</SPAN> cur <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>SearchCursor<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">,</SPAN> flds<SPAN class="punctuation token">,</SPAN> spatial_reference<SPAN class="operator token">=</SPAN>SR<SPAN class="punctuation token">,</SPAN> explode_to_points<SPAN class="operator token">=</SPAN>to_pnts<SPAN class="punctuation token">)</SPAN> a <SPAN class="operator token">=</SPAN> cur<SPAN class="punctuation token">.</SPAN>_as_narray<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> a <SPAN class="operator token">=</SPAN> _view_<SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">return</SPAN> a‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN> ---- Results .... Essentially you have a simplified list of X, Y coordinates since the 'shp' was defined as 'SHAPE@X' and 'SHAPE@Y' with 'explode_to_points' set to True (False, returns centroids). Sadly you can't reconstruct the polygons unless you deal with the which points belong to what polygon. array([[ 300020., 5000000.], &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [ 300010., 5000000.], &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [ 300010., 5000010.], &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ..., &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [ 300002., 5000002.], &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [ 300008., 5000002.], &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [ 300005., 5000008.]])‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>
---- The FeatureClassToNumPyArray Approach ---- This produces the same results above, requires the same sort of inputs.  Timing shows that they are strongly related, especially since _as_narray has a fields and dtype property. <SPAN class="keyword token">def</SPAN> <SPAN class="token function">fc_xy</SPAN><SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"""Return the x,y coordinates for points in a featureclass (in_fc) using a data access searchcursor. """</SPAN> SR <SPAN class="operator token">=</SPAN> getSR<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">)</SPAN> a <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>FeatureClassToNumPyArray<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SHAPE@X'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SHAPE@Y'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> spatial_reference<SPAN class="operator token">=</SPAN>SR<SPAN class="punctuation token">,</SPAN> explode_to_points<SPAN class="operator token">=</SPAN><SPAN class="token boolean">True</SPAN><SPAN class="punctuation token">)</SPAN> a <SPAN class="operator token">=</SPAN> _view_<SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">return</SPAN> a‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>
---- Retrieving shape objects ---- If you want to use arcpy directly because of the builtin methods, you need the contents of the 'shape' fields using SHAPE@' rather than just extracting the X and Y coordinates as in the previous example <SPAN class="keyword token">def</SPAN> <SPAN class="token function">fc_shapes</SPAN><SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">,</SPAN> as_array<SPAN class="operator token">=</SPAN><SPAN class="token boolean">True</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"""Derive, arcpy geometry objects from a featureClass searchcursor. Parameters ---------- in_fc : text Path to the input featureclass as_array: boolean True, return an object array of arcpy polygon objects. False, returns a list. """</SPAN> SR <SPAN class="operator token">=</SPAN> getSR<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">with</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>SearchCursor<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SHAPE@'</SPAN><SPAN class="punctuation token">,</SPAN> None<SPAN class="punctuation token">,</SPAN> SR<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> cursor<SPAN class="punctuation token">:</SPAN> a <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">for</SPAN> row <SPAN class="keyword token">in</SPAN> cursor<SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">if</SPAN> as_array<SPAN class="punctuation token">:</SPAN> <SPAN class="keyword token">return</SPAN> np<SPAN class="punctuation token">.</SPAN>asarray<SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">return</SPAN> a ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN> ---- Put it to work ---- polys = fc_shapes(in_fc, as_array=True) polys array([<Polygon object at 0x197f1bcebe0[0x197f0199968]>, <Polygon object at 0x197f1bcec18[0x197e9b48da0]>, <Polygon object at 0x197f1bceb70[0x197f005b738]>, <Polygon object at 0x197f1bceb38[0x197f005b5a8]>, <Polygon object at 0x197f1bceac8[0x197f005b760]>], dtype=object)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>
---- Geometry as a structured array ---- Nothing fancy, but there is an integer ID field indicating which feature a point belongs to and the coordinates. A simpler version of the above... just an ID field and coordinates.   <SPAN class="keyword token">def</SPAN> <SPAN class="token function">fc_xyID</SPAN><SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">,</SPAN> to_pnts<SPAN class="operator token">=</SPAN><SPAN class="token boolean">True</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"""Convert featureclass geometry (in_fc) to a simple 2D structured array with ID, X, Y values. Optionally convert to points, otherwise centroid. """</SPAN> SR <SPAN class="operator token">=</SPAN> getSR<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">)</SPAN> flds <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'OID@'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SHAPE@X'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SHAPE@Y'</SPAN><SPAN class="punctuation token">]</SPAN> cur <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>SearchCursor<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">,</SPAN> flds<SPAN class="punctuation token">,</SPAN> spatial_reference<SPAN class="operator token">=</SPAN>SR<SPAN class="punctuation token">,</SPAN> explode_to_points<SPAN class="operator token">=</SPAN>to_pnts<SPAN class="punctuation token">)</SPAN> a <SPAN class="operator token">=</SPAN> cur<SPAN class="punctuation token">.</SPAN>_as_narray<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> a<SPAN class="punctuation token">.</SPAN>dtype <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">'IDs'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'<i4'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="string token">'X_s'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'<f8'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="string token">'Y_s'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'<f8'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">return</SPAN> a‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN> ---- The results ---- a = fc_xyID(in_fc, to_pnts=True) a array([(1, 300010., 5000000.), (1, 300000., 5000000.), (1, 300000., 5000010.), (1, 300010., 5000010.),(1, 300010., 5000000.), ... snip (5, 300020., 5000010.),(5, 300022., 5000010.), (5, 300025., 5000002.), (5, 300028., 5000010.), (5, 300030., 5000010.),(5, 300026., 5000000.), (5, 300024., 5000000.), (5, 300020., 5000010.)], dtype=[('IDs', '<i4'), ('X_s', '<f8'), ('Y_s', '<f8')])‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN> The polygon ID that each point belongs to is retained, however, it is replicated many times and the null points separating polygon parts is removed.

--------------------------------------------------------------------------

Helper functions

Helper Functions 

_view_   .... view structured arrays as an unstructured array
_getSR  .... spatial reference for a featureclass
<SPAN class="keyword token">def</SPAN> <SPAN class="token function">_view_</SPAN><SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"""Return a view of the array using the dtype and length Notes ----- The is a quick function. The expectation is that the array contains a uniform dtype (e.g 'f8'). For example, coordinate values in the form ``dtype([('X', '<f8'), ('Y', '<f8')])`` maybe with a Z. References ---------- ``structured_to_unstructured`` in np.lib.recfunctions and its imports. `<https://github.com/numpy/numpy/blob/master/numpy/lib/recfunctions.py>`_. """</SPAN> v <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>version<SPAN class="punctuation token">.</SPAN>version<SPAN class="punctuation token">.</SPAN>split<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'.'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="comment token"># version check</SPAN> <SPAN class="keyword token">if</SPAN> int<SPAN class="punctuation token">(</SPAN>v<SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">>=</SPAN> <SPAN class="number token">16</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="keyword token">from</SPAN> numpy<SPAN class="punctuation token">.</SPAN>lib<SPAN class="punctuation token">.</SPAN>recfunctions <SPAN class="keyword token">import</SPAN> structured_to_unstructured <SPAN class="keyword token">as</SPAN> stu <SPAN class="keyword token">return</SPAN> stu<SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN> names <SPAN class="operator token">=</SPAN> a<SPAN class="punctuation token">.</SPAN>dtype<SPAN class="punctuation token">.</SPAN>names z <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>zeros<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">.</SPAN>shape<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">2</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> dtype<SPAN class="operator token">=</SPAN>np<SPAN class="punctuation token">.</SPAN>float<SPAN class="punctuation token">)</SPAN> z<SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> a<SPAN class="punctuation token">[</SPAN>names<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN> z<SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> a<SPAN class="punctuation token">[</SPAN>names<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">return</SPAN> z‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>
Result... a <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">300015</SPAN><SPAN class="punctuation token">.</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000005</SPAN><SPAN class="punctuation token">.</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300005</SPAN><SPAN class="punctuation token">.</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000015</SPAN><SPAN class="punctuation token">.</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300010.49</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000010.59</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> dtype<SPAN class="operator token">=</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">'SHAPE@X'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'<f8'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="string token">'SHAPE@Y'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'<f8'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN> _view_<SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">)</SPAN> array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300015</SPAN><SPAN class="punctuation token">.</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000005</SPAN><SPAN class="punctuation token">.</SPAN> <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300005</SPAN><SPAN class="punctuation token">.</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000015</SPAN><SPAN class="punctuation token">.</SPAN> <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300010.49</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000010.59</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>
getSR .... <SPAN class="keyword token">def</SPAN> <SPAN class="token function">getSR</SPAN><SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"""Return the spatial reference of a featureclass"""</SPAN> desc <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>Describe<SPAN class="punctuation token">(</SPAN>in_fc<SPAN class="punctuation token">)</SPAN> SR <SPAN class="operator token">=</SPAN> desc<SPAN class="punctuation token">[</SPAN><SPAN class="string token">'spatialReference'</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">return</SPAN> SR‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN> Which you can use for basic spatial reference facts ( dir(SR) for a full list ) SR<SPAN class="punctuation token">.</SPAN>type<SPAN class="punctuation token">,</SPAN> SR<SPAN class="punctuation token">.</SPAN>name<SPAN class="punctuation token">,</SPAN> SR<SPAN class="punctuation token">.</SPAN>factoryCode<SPAN class="punctuation token">,</SPAN> SR<SPAN class="punctuation token">.</SPAN>centralMeridian<SPAN class="punctuation token">,</SPAN> SR<SPAN class="punctuation token">.</SPAN>falseEasting <SPAN class="punctuation token">(</SPAN><SPAN class="string token">'Projected'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'NAD_1983_CSRS_MTM_9'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">2951</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="number token">76.5</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">304800.0</SPAN><SPAN class="punctuation token">)</SPAN>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Other links

/blogs/dan_patterson/2019/03/17/geometry-in-numpy-1