Mode standalone: rename resulting file to ID.py, set executable

Author: plepe

doc/API.md

@@ -29,12 +29,12 @@ style_elements_z_index | float[] | z-index for each style element.
 Notes:
 * `!bbox!` and `!scale_denominator!` will be replaced by Mapnik by the current bounding box resp. scale denominator. See [zoom-to-scale.txt](https://trac.openstreetmap.org/browser/subversion/applications/rendering/mapnik/zoom-to-scale.txt) for valid values.
 
-### Mode 'standalone': file pgmapcss_{style_id}.py
-When compiling in 'standalone' mode, a file pgmapcss_{style_id}.py will be created, which can be used either from command line or as CGI script. In any case it will produce GeoJSON output. See below for details.
+### Mode 'standalone': file {style_id}.py
+When compiling in 'standalone' mode, a file {style_id}.py will be created, which can be used either from command line or as CGI script. In any case it will produce GeoJSON output. See below for details.
 
 #### command line
 ```
-usage: pgmapcss_{style_id}.py [-h] [-b BOUNDS] [-s SCALE]
+usage: {style_id}.py [-h] [-b BOUNDS] [-s SCALE]
                        [-P PARAMETERS [PARAMETERS ...]] [--lang LANG]
 
 Executes the compiled map style and prints resulting objects.

pgmapcss/main.py

@@ -223,7 +223,9 @@ def main():
         pgmapcss.db.install(style_id, style, conn)
         pgmapcss.renderer.process_renderer(style_id, args, stat, conn)
     elif stat['mode'] == 'standalone':
-        open('pgmapcss_' + style_id + '.py', 'w').write(style['function_match'])
+        open(style_id + '.py', 'w').write(style['function_match'])
+        os.chmod(style_id + '.py', 0o755)
+        print('Created executable {}.py'.format(style_id))
 
     pgmapcss.icons.process_icons(style_id, args, stat, conn)
     pgmapcss.symbols.process_symbols(style_id, args, stat, conn)