Real-time forecasts: 1 param, 1 date

Retrieving one field (total precipitation here) for all time steps and  for the forecast starting on 1st  May 2015:

#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
    "class": "s2",
    "dataset": "s2s",
    "date": "2015-05-01",
    "expver": "prod",
    "levtype": "sfc",
    "origin": "lfpw",
    "param": "tp",
    "step": "24/to/1464/by/24",
    "stream": "enfo",
    "target": "CHANGEME",
    "time": "00",
    "type": "cf",
})
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
    "class": "s2",
    "dataset": "s2s",
    "date": "2015-05-01",
    "expver": "prod",
    "levtype": "sfc",
    "origin": "lfpw",
    "param": "tp",
    "step": "24/to/1464/by/24",
    "stream": "enfo",
    "target": "CHANGEME",
    "time": "00", 
    "number": "1/to/50",
    "type": "pf",
 })

Real-time forecasts: 1 param, series of dates

Retrieving one field (total precipitation here) for all time steps and  for all the forecast starting between  1st May and 1st June 2015:

#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
    "class": "s2",
    "dataset": "s2s",
    "date": "2015-05-01/2015-06-01",
    "expver": "prod",
    "levtype": "sfc",
    "origin": "lfpw",
    "param": "tp",
    "step": "24/to/1464/by/24",
    "stream": "enfo",
    "target": "CHANGEME",
    "time": "00",
    "type": "cf",
})
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
    "class": "s2",
    "dataset": "s2s",
    "date": "2015-05-01/2015-06-01",
    "expver": "prod",
    "levtype": "sfc",
    "origin": "lfpw",
    "param": "tp",
    "step": "24/to/1464/by/24",
    "stream": "enfo",
    "target": "CHANGEME",
    "time": "00", 
    "number": "1/to/50",
    "type": "pf",
 })