#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2017-2020 Satpy developers
#
# This file is part of satpy.
#
# satpy is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# satpy. If not, see <http://www.gnu.org/licenses/>.
"""Module for testing the satpy.readers.netcdf_utils module."""
import os
import unittest
import numpy as np
try:
from satpy.readers.netcdf_utils import NetCDF4FileHandler
except ImportError:
# fake the import so we can at least run the tests in this file
NetCDF4FileHandler = object # type: ignore
[docs]class FakeNetCDF4FileHandler(NetCDF4FileHandler):
"""Swap-in NetCDF4 File Handler for reader tests to use."""
def __init__(self, filename, filename_info, filetype_info,
auto_maskandscale=False, xarray_kwargs=None,
cache_var_size=0, cache_handle=False, extra_file_content=None):
"""Get fake file content from 'get_test_content'."""
# unused kwargs from the real file handler
del auto_maskandscale
del xarray_kwargs
del cache_var_size
del cache_handle
if NetCDF4FileHandler is object:
raise ImportError("Base 'NetCDF4FileHandler' could not be "
"imported.")
super(NetCDF4FileHandler, self).__init__(filename, filename_info, filetype_info)
self.file_content = self.get_test_content(filename, filename_info, filetype_info)
if extra_file_content:
self.file_content.update(extra_file_content)
[docs] def get_test_content(self, filename, filename_info, filetype_info):
"""Mimic reader input file content.
Args:
filename (str): input filename
filename_info (dict): Dict of metadata pulled from filename
filetype_info (dict): Dict of metadata from the reader's yaml config for this file type
Returns: dict of file content with keys like:
- 'dataset'
- '/attr/global_attr'
- 'dataset/attr/global_attr'
- 'dataset/shape'
- 'dataset/dimensions'
- '/dimension/my_dim'
"""
raise NotImplementedError("Fake File Handler subclass must implement 'get_test_content'")
[docs]class TestNetCDF4FileHandler(unittest.TestCase):
"""Test NetCDF4 File Handler Utility class."""
[docs] def setUp(self):
"""Create a test NetCDF4 file."""
from netCDF4 import Dataset
with Dataset('test.nc', 'w') as nc:
# Create dimensions
nc.createDimension('rows', 10)
nc.createDimension('cols', 100)
# Create Group
g1 = nc.createGroup('test_group')
# Add datasets
ds1_f = g1.createVariable('ds1_f', np.float32,
dimensions=('rows', 'cols'))
ds1_f[:] = np.arange(10. * 100).reshape((10, 100))
ds1_i = g1.createVariable('ds1_i', np.int32,
dimensions=('rows', 'cols'))
ds1_i[:] = np.arange(10 * 100).reshape((10, 100))
ds2_f = nc.createVariable('ds2_f', np.float32,
dimensions=('rows', 'cols'))
ds2_f[:] = np.arange(10. * 100).reshape((10, 100))
ds2_i = nc.createVariable('ds2_i', np.int32,
dimensions=('rows', 'cols'))
ds2_i[:] = np.arange(10 * 100).reshape((10, 100))
ds2_s = nc.createVariable("ds2_s", np.int8,
dimensions=("rows",))
ds2_s[:] = np.arange(10)
ds2_sc = nc.createVariable("ds2_sc", np.int8, dimensions=())
ds2_sc[:] = 42
# Add attributes
nc.test_attr_str = 'test_string'
nc.test_attr_int = 0
nc.test_attr_float = 1.2
nc.test_attr_str_arr = np.array(b"test_string2")
g1.test_attr_str = 'test_string'
g1.test_attr_int = 0
g1.test_attr_float = 1.2
for d in [ds1_f, ds1_i, ds2_f, ds2_i]:
d.test_attr_str = 'test_string'
d.test_attr_int = 0
d.test_attr_float = 1.2
[docs] def tearDown(self):
"""Remove the previously created test file."""
os.remove('test.nc')
[docs] def test_all_basic(self):
"""Test everything about the NetCDF4 class."""
import xarray as xr
from satpy.readers.netcdf_utils import NetCDF4FileHandler
file_handler = NetCDF4FileHandler('test.nc', {}, {})
self.assertEqual(file_handler['/dimension/rows'], 10)
self.assertEqual(file_handler['/dimension/cols'], 100)
for ds in ('test_group/ds1_f', 'test_group/ds1_i', 'ds2_f', 'ds2_i'):
self.assertEqual(file_handler[ds].dtype, np.float32 if ds.endswith('f') else np.int32)
self.assertTupleEqual(file_handler[ds + '/shape'], (10, 100))
self.assertEqual(file_handler[ds + '/dimensions'], ("rows", "cols"))
self.assertEqual(file_handler[ds + '/attr/test_attr_str'], 'test_string')
self.assertEqual(file_handler[ds + '/attr/test_attr_int'], 0)
self.assertEqual(file_handler[ds + '/attr/test_attr_float'], 1.2)
test_group = file_handler['test_group']
self.assertTupleEqual(test_group['ds1_i'].shape, (10, 100))
self.assertTupleEqual(test_group['ds1_i'].dims, ('rows', 'cols'))
self.assertEqual(file_handler['/attr/test_attr_str'], 'test_string')
self.assertEqual(file_handler['/attr/test_attr_str_arr'], 'test_string2')
self.assertEqual(file_handler['/attr/test_attr_int'], 0)
self.assertEqual(file_handler['/attr/test_attr_float'], 1.2)
global_attrs = {
'test_attr_str': 'test_string',
'test_attr_str_arr': 'test_string2',
'test_attr_int': 0,
'test_attr_float': 1.2
}
self.assertEqual(file_handler['/attrs'], global_attrs)
self.assertIsInstance(file_handler.get('ds2_f')[:], xr.DataArray)
self.assertIsNone(file_handler.get('fake_ds'))
self.assertEqual(file_handler.get('fake_ds', 'test'), 'test')
self.assertTrue('ds2_f' in file_handler)
self.assertFalse('fake_ds' in file_handler)
self.assertIsNone(file_handler.file_handle)
self.assertEqual(file_handler["ds2_sc"], 42)
[docs] def test_listed_variables(self):
"""Test that only listed variables/attributes area collected."""
from satpy.readers.netcdf_utils import NetCDF4FileHandler
filetype_info = {
'required_netcdf_variables': [
'test_group/attr/test_attr_str',
'attr/test_attr_str',
]
}
file_handler = NetCDF4FileHandler('test.nc', {}, filetype_info)
assert len(file_handler.file_content) == 2
assert 'test_group/attr/test_attr_str' in file_handler.file_content
assert 'attr/test_attr_str' in file_handler.file_content
[docs] def test_listed_variables_with_composing(self):
"""Test that composing for listed variables is performed."""
from satpy.readers.netcdf_utils import NetCDF4FileHandler
filetype_info = {
'required_netcdf_variables': [
'test_group/{some_parameter}/attr/test_attr_str',
'test_group/attr/test_attr_str',
],
'variable_name_replacements': {
'some_parameter': [
'ds1_f',
'ds1_i',
],
'another_parameter': [
'not_used'
],
}
}
file_handler = NetCDF4FileHandler('test.nc', {}, filetype_info)
assert len(file_handler.file_content) == 3
assert 'test_group/ds1_f/attr/test_attr_str' in file_handler.file_content
assert 'test_group/ds1_i/attr/test_attr_str' in file_handler.file_content
assert not any('not_used' in var for var in file_handler.file_content)
assert not any('some_parameter' in var for var in file_handler.file_content)
assert not any('another_parameter' in var for var in file_handler.file_content)
assert 'test_group/attr/test_attr_str' in file_handler.file_content
[docs] def test_caching(self):
"""Test that caching works as intended."""
from satpy.readers.netcdf_utils import NetCDF4FileHandler
h = NetCDF4FileHandler("test.nc", {}, {}, cache_var_size=1000,
cache_handle=True)
self.assertIsNotNone(h.file_handle)
self.assertTrue(h.file_handle.isopen())
self.assertEqual(sorted(h.cached_file_content.keys()),
["ds2_s", "ds2_sc"])
# with caching, these tests access different lines than without
np.testing.assert_array_equal(h["ds2_s"], np.arange(10))
np.testing.assert_array_equal(h["test_group/ds1_i"],
np.arange(10 * 100).reshape((10, 100)))
# check that root variables can still be read from cached file object,
# even if not cached themselves
np.testing.assert_array_equal(
h["ds2_f"],
np.arange(10. * 100).reshape((10, 100)))
h.__del__()
self.assertFalse(h.file_handle.isopen())
[docs] def test_filenotfound(self):
"""Test that error is raised when file not found."""
from satpy.readers.netcdf_utils import NetCDF4FileHandler
with self.assertRaises(IOError):
NetCDF4FileHandler("/thisfiledoesnotexist.nc", {}, {})
[docs] def test_get_and_cache_npxr_is_xr(self):
"""Test that get_and_cache_npxr() returns xr.DataArray."""
import xarray as xr
from satpy.readers.netcdf_utils import NetCDF4FileHandler
file_handler = NetCDF4FileHandler('test.nc', {}, {}, cache_handle=True)
data = file_handler.get_and_cache_npxr('test_group/ds1_f')
assert isinstance(data, xr.DataArray)
[docs] def test_get_and_cache_npxr_data_is_cached(self):
"""Test that the data are cached when get_and_cache_npxr() is called."""
from satpy.readers.netcdf_utils import NetCDF4FileHandler
file_handler = NetCDF4FileHandler('test.nc', {}, {}, cache_handle=True)
data = file_handler.get_and_cache_npxr('test_group/ds1_f')
# Delete the dataset from the file content dict, it should be available from the cache
del file_handler.file_content["test_group/ds1_f"]
data2 = file_handler.get_and_cache_npxr('test_group/ds1_f')
assert np.all(data == data2)
[docs]class TestNetCDF4FsspecFileHandler:
"""Test the remote reading class."""
[docs] def test_default_to_netcdf4_lib(self):
"""Test that the NetCDF4 backend is used by default."""
import os
import tempfile
import h5py
from satpy.readers.netcdf_utils import NetCDF4FsspecFileHandler
with tempfile.TemporaryDirectory() as tmpdir:
# Create an empty HDF5
fname = os.path.join(tmpdir, "test.nc")
fid = h5py.File(fname, "w")
fid.close()
fh = NetCDF4FsspecFileHandler(fname, {}, {})
assert fh._use_h5netcdf is False
[docs] def test_use_h5netcdf_for_file_not_accessible_locally(self):
"""Test that h5netcdf is used for files that are not accesible locally."""
from unittest.mock import patch
fname = "s3://bucket/object.nc"
with patch("h5netcdf.File") as h5_file:
with patch("satpy.readers.netcdf_utils.open_file_or_filename"):
from satpy.readers.netcdf_utils import NetCDF4FsspecFileHandler
fh = NetCDF4FsspecFileHandler(fname, {}, {})
h5_file.assert_called_once()
assert fh._use_h5netcdf