[CG] : add fct dump database

pycen/tools.py

@@ -405,4 +405,13 @@ def Polygons_to_MultiPolygon(df,geom_col=None):
   poly[geom_col] = [MultiPolygon([geom]) for geom in df.loc[df.geom_type=='Polygon',geom_col] ]
   df = concat([multi,poly])
   df.sort_index(inplace=True)
-  return df
+  return df
+
+def dump_bd(host,bd_name, user):
+  from os import system
+  from datetime import datetime as dt
+  date = dt.today().date().isoformat().replace('-','')
+  cmd = 'pg_dump -h {h} -U {u} -W -F c {bd} > {bd}_{dat}.dump'.format(
+    h=host,u=user,bd=bd_name,dat=date
+  )
+  system(cmd)