[CG] : add read layer

pycen/tools.py

@@ -152,6 +152,35 @@ def _set_geom(df, hex=True, crs=2154):
   
   return df
 
+def _get_layer(table,con,schema,columns:list=None,args:None=None,bbox:None=None):
+  import geopandas as gpd
+  sql = '''
+    SELECT {cols} FROM {sch}.{tab} t
+  '''.format(
+      cols = ','.join(columns) if columns else '*',
+      sch=schema,
+      tab=table)
+  if args or bbox:
+    sql += ' WHERE '
+    if args :
+      w = []
+      for a in args:
+        w.append('{col} {sym} {val}'.format(
+          col = 't.'+a, 
+          sym = '=' if isinstance(args[a],str) else 'IN',
+          val = "'"+args[a]+"'" if isinstance(args[a],str) else tuple(args[a])
+        ))
+    b = []
+    if bbox :
+      b = ['''
+        ST_INTERSECTS(t.geom,'SRID={epsg};{poly}')
+      '''.format(
+        epsg = 2154,
+        poly = bbox,
+      )]
+    sql += ' AND '.join([*w,*b])
+    return gpd.read_postgis(sql,con)
+
 
 
 def _get_param(schema, param_table, type_table=None, type_court=True):