To access ECMWF you will need an API KEY that can be optained at https://api-test.ecmwf.int/v1/key/. A full description of the ECMWF WEB API can be found at { "ECMWF" : "API", "version" : 1 }.
#!/usr/bin/python from ecmwf import ECMWFDataServer server = ECMWFDataServer( 'http://tigge-portal.ecmwf.int/d/dataserver/', '30b1c1a4d9760fddeaea34c4c1fbb1f8', 'baudouin.raoult@ecmwf.int' ) server.retrieve({ 'dataset' : "tigge", 'step' : "24/to/120/by/24", 'number' : "all", 'levtype' : "sl", 'date' : "20071001/to/20071003", 'time' : "00/12", 'origin' : "all", 'type' : "pf", 'param' : "tp", 'area' : "70/-130/30/-60", 'grid' : "2/2", 'target' : "data.grib" })