I’m trying to write Python script to convert points (vertices) with Lat/Long to Polygons

FredF

I’m trying to write Python script to convert points (vertices) with Lat/Long to Polygons.  The points are stored in Excel sheet and these points representing the edges of an area structure. I have the Structure ID’s, the order no of the points, Lat and Long. The no of points that can draw a polygon vary from structures to another, for example in case of a soccer filed there will be 4 points but in case of an outdoor recreation area I might be having 8 – 10 points.  So the no of points is not fixes for every area structure (polygon). Thanks for your help.

curtvprice

The trickiest part may be getting your boundaries into a python list. If the data are in excel you will probably need to structure them in a table format so ArcGIS can read them that way, 

FLD1    FLD2
poly1   1
x       y
x       y
x       y
x       y
poly2   2
x       y
...‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

These would come in as two string fields, which you would then need run a SearchCursor loop over to construct Python data in a list like this:

<SPAN class="punctuation token">[</SPAN><SPAN class="string token">"poly1"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">1</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">[</SPAN>x<SPAN class="punctuation token">,</SPAN>y<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>x<SPAN class="punctuation token">,</SPAN>y<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>x<SPAN class="punctuation token">,</SPAN>y<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>x<SPAN class="punctuation token">,</SPAN>y<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="punctuation token">[</SPAN><SPAN class="string token">"poly2"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">2</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">[</SPAN>x<SPAN class="punctuation token">,</SPAN>y<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</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>

Then, if there aren't holes involved, writing polygon geometry is pretty straight forward if you follow the steps:

• construct an array of points
• create a polygon geometry
• write to a shape field inside an update cursor

I believe the examples in the help are useful but way too sparse. Here's a script I posted to GeoNet that worked for me:

• Writing polygon geometry with holes  

There are also many other examples on GeoNet and elsewhere to consult:

arcpy - Python script that creates polygon feature class with given coordinates (nice simple example) 

Bug?: Creating polygons with holes using Arcpy 

Examples of Geometry object - polygon and intersect‌