Reading multiple files

First we prepare the data.

[1]:

import earthkit.data as ekd
ekd.download_example_file(["test.grib", "test4.grib"])

[2]:

!test -d _grib_dir_no_sql || (mkdir -p _grib_dir_no_sql; cp -f test.grib test4.grib _grib_dir_no_sql/)

Multiple GRIB files can be read in various ways:

Option 1: using wildcards

[3]:

fs = ekd.from_source("file", "test*.grib")

[4]:

len(fs)

[4]:

12

[5]:

fs

[5]:
GribMultiFieldList(GRIBReader(test.grib),GRIBReader(test4.grib),GRIBReader(test6.grib))

Option 2: using a list

[6]:

fs = ekd.from_source("file", ["test.grib", "test4.grib"])

[7]:

len(fs)

[7]:

6

[8]:

fs

[8]:
GribMultiFieldList(GRIBReader(test.grib),GRIBReader(test4.grib))

Option 3: reading all files in a directory

[9]:

fs = ekd.from_source("file", "./_grib_dir_no_sql")

[10]:

len(fs)

[10]:

6

[11]:

fs

[11]:
GribMultiFieldList(GRIBReader(./_grib_dir_no_sql/test.grib),GRIBReader(./_grib_dir_no_sql/test4.grib))

Working with the object

The resulting GRIB object behaves in the same way as if it was created from a single file:

[12]:

fs.ls()

[12]:
centre shortName typeOfLevel level dataDate dataTime stepRange dataType number gridType
0 ecmf 2t surface 0 20200513 1200 0 an 0 regular_ll
1 ecmf msl surface 0 20200513 1200 0 an 0 regular_ll
2 ecmf t isobaricInhPa 500 20070101 1200 0 an 0 regular_ll
3 ecmf z isobaricInhPa 500 20070101 1200 0 an 0 regular_ll
4 ecmf t isobaricInhPa 850 20070101 1200 0 an 0 regular_ll
5 ecmf z isobaricInhPa 850 20070101 1200 0 an 0 regular_ll 
[13]:

fs[2]

[13]:

GribField(t,500,20070101,1200,0,0)

[14]:

g = fs[1:6]
g.ls()

[14]:
centre shortName typeOfLevel level dataDate dataTime stepRange dataType number gridType
0 ecmf msl surface 0 20200513 1200 0 an 0 regular_ll
1 ecmf t isobaricInhPa 500 20070101 1200 0 an 0 regular_ll
2 ecmf z isobaricInhPa 500 20070101 1200 0 an 0 regular_ll
3 ecmf t isobaricInhPa 850 20070101 1200 0 an 0 regular_ll
4 ecmf z isobaricInhPa 850 20070101 1200 0 an 0 regular_ll 
[15]:

g = fs[3:6].sel(param="z").order_by("level")
g.ls()

[15]:
centre shortName typeOfLevel level dataDate dataTime stepRange dataType number gridType
0 ecmf z isobaricInhPa 500 20070101 1200 0 an 0 regular_ll
1 ecmf z isobaricInhPa 850 20070101 1200 0 an 0 regular_ll