[SOLVED] Rename output file with ERA5 daily statistics calculator API

Rename output file with ERA5 daily statistics calculator API

I am trying to download ERA5 daily statistics from hourly ones with the ERA5 daily statistics calculator. Since I need multiple years and months I am using API. Following the instruction in the documentation. I created the following python script:

import cdsapi
c = cdsapi.Client()
YEARS = [
    "1991", "1992"
]
MONTHS = [
 "01", "02", "03"
]  
for year in YEARS:
    for month in MONTHS:
        result = c.service( "tool.toolbox.orchestrator.workflow",
params={
            "realm": "user-apps",
            "project": "app-c3s-daily-era5-statistics",
            "version": "master",
            "kwargs": {
                "dataset": "reanalysis-era5-single-levels",
                "product_type": "reanalysis",
                "variable": "2m_temperature",
                "statistic": "daily_minimum",
                "year": year,
                "month": month,
                "time_zone": "UTC+00:00",
                "frequency": "1-hourly",
                "grid": "0.25/0.25",
                "area": {"lat": [-90, 90], "lon": [-180, 180]}
            },
            "workflow_name": "application" 
        }, 
    )
        c.download(result)

The downloaded files have a default name that is not explicative. I would like to specify the file name like Tmin_year_month.nc

Solution

You just need to pass the desired filename as the second argument to the download function:

file="my_output_file.nc"
c.download(result,[file])

NOTE! Unlike the normal api for data, the second argument needs to be a list, otherwise the download procedure will take [0] of the filename string and return the file called "m" in my example. I already flagged this to ECMWF as a feature (bug!) to be corrected. I also mentioned that they could add this to the Wiki.