Saving resampled area fails with AttributeError: 'NoneType' object has no attribute 'split'

[gerritholl]

Saving a scene resampled to an area with certain properties fails with AttributeError: 'NoneType' object has no attribute 'split':

from satpy import Scene
from satpy.utils import debug_on; debug_on()
sc = Scene(
        filenames=["/media/nas/x21308/scratch/hrpt_metop03_20210323_1809_12327.l1b"],
        reader=["avhrr_l1b_aapp"])
sc.load(["4"])
ls = sc.resample("nqceur250m")
ls.save_dataset("4",
        "/tmp/test.tif",
        writer="ninjotiff",
        physic_unit="C",
        sat_id=7900014,
        chan_id=900015,
        data_cat="PORN",
        nbits=8,
        data_source="HRPT",
        ch_min_measurement_unit=40,
        ch_max_measurement_unit=-87.5)

Area in question is defined as:

nqceur250m:
  description: nqceur250m
  projection:
    proj: longlat
    lon_0: 0.0
    lat_0: 50.0
    lat_ts: 0.0
    ellps: WGS84
  shape:
    height: 8000
    width: 16000
  area_extent:
    lower_left_xy: [-0.22689123196293604, 0.7155956398261123]
    upper_right_xy: [0.401424157162369, 1.0297336121682172]

Executing this code results in:

[DEBUG: 2021-09-27 18:14:26 : satpy.readers.yaml_reader] Reading ('/data/gholl/checkouts/satpy/satpy/etc/readers/avhrr_l1b_aapp.yaml',)
[DEBUG: 2021-09-27 18:14:26 : satpy.readers.yaml_reader] Assigning to avhrr_l1b_aapp: ['/media/nas/x21308/scratch/hrpt_metop03_20210323_1809_12327.l1b']
[DEBUG: 2021-09-27 18:14:26 : satpy.readers.aapp_l1b] Reading time 0:00:00.003269
[DEBUG: 2021-09-27 18:14:26 : satpy.composites.config_loader] Looking for composites config file avhrr-3.yaml
[DEBUG: 2021-09-27 18:14:26 : satpy.composites.config_loader] Looking for composites config file visir.yaml
[DEBUG: 2021-09-27 18:14:26 : satpy.readers.yaml_reader] No coordinates found for DataID(name='latitude', resolution=1050, modifiers=())
[DEBUG: 2021-09-27 18:14:26 : satpy.readers.yaml_reader] No coordinates found for DataID(name='longitude', resolution=1050, modifiers=())
[DEBUG: 2021-09-27 18:14:26 : satpy.scene] Resampling DataID(name='4', wavelength=WavelengthRange(min=10.3, central=10.8, max=11.3, unit='µm'), resolution=1050, calibration=<calibration.brightness_temperature>, modifiers=())
[INFO: 2021-09-27 18:14:26 : satpy.scene] Not reducing data before resampling.
[INFO: 2021-09-27 18:14:26 : satpy.resample] Using default KDTree resampler
[DEBUG: 2021-09-27 18:14:26 : satpy.resample] Check if ./resample_lut-31dcaed3f5e41d8b6d60b228206fe9fd414aa9f2.npz exists
[DEBUG: 2021-09-27 18:14:26 : satpy.resample] Computing kd-tree parameters
/data/gholl/miniconda3/envs/py39b/lib/python3.9/site-packages/pyresample/kd_tree.py:1025: DeprecationWarning: `np.float` is a deprecated alias for the builtin `float`. To silence this warning, use `float` by itself. Doing this will not modify any behavior and is safe. If you specifically wanted the numpy scalar type, use `np.float64` here.
Deprecated in NumPy 1.20; for more details and guidance: https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations
  input_coords = input_coords.astype(np.float)
/data/gholl/miniconda3/envs/py39b/lib/python3.9/site-packages/pyresample/kd_tree.py:1047: DeprecationWarning: `np.int` is a deprecated alias for the builtin `int`. To silence this warning, use `int` by itself. Doing this will not modify any behavior and is safe. When replacing `np.int`, you may wish to use e.g. `np.int64` or `np.int32` to specify the precision. If you wish to review your current use, check the release note link for additional information.
Deprecated in NumPy 1.20; for more details and guidance: https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations
  radius=self.radius_of_influence, dtype=np.int,
[DEBUG: 2021-09-27 18:14:26 : satpy.resample] Resampling where-9f3f1f4d3c037162a3d408d41ea4566f
[DEBUG: 2021-09-27 18:14:26 : satpy.writers] Reading ['/data/gholl/checkouts/satpy/satpy/etc/writers/ninjotiff.yaml']
/data/gholl/checkouts/pyninjotiff/pyninjotiff/tifffile.py:154: UserWarning: failed to import the optional _tifffile C extension module.
Loading of some compressed images will be slow.
Tifffile.c can be obtained at http://www.lfd.uci.edu/~gohlke/
  warnings.warn(
[DEBUG: 2021-09-27 18:14:26 : satpy.writers] Enhancement configuration options: [{'name': 'stretch', 'method': <function stretch at 0x7f035b1ab040>, 'kwargs': {'stretch': 'linear'}}]
[DEBUG: 2021-09-27 18:14:26 : trollimage.xrimage] Applying stretch linear with parameters {}
[DEBUG: 2021-09-27 18:14:26 : trollimage.xrimage] Perform a linear contrast stretch.
[DEBUG: 2021-09-27 18:14:26 : trollimage.xrimage] Calculate the histogram quantiles: 
[DEBUG: 2021-09-27 18:14:26 : trollimage.xrimage] Left and right quantiles: 0.005 0.005
[INFO: 2021-09-27 18:14:27 : pyninjotiff.ninjotiff] Will generate single band product
/data/gholl/miniconda3/envs/py39b/lib/python3.9/site-packages/pyproj/crs/crs.py:1216: UserWarning: You will likely lose important projection information when converting to a PROJ string from another format. See: https://proj.org/faq.html#what-is-the-best-format-for-describing-coordinate-reference-systems
  return self._crs.to_proj4(version=version)
/data/gholl/miniconda3/envs/py39b/lib/python3.9/site-packages/pyproj/crs/crs.py:1216: UserWarning: You will likely lose important projection information when converting to a PROJ string from another format. See: https://proj.org/faq.html#what-is-the-best-format-for-describing-coordinate-reference-systems
  return self._crs.to_proj4(version=version)
Traceback (most recent call last):
  File "/data/gholl/checkouts/protocode/mwe/ninjotiff-crash.py", line 8, in <module>
    ls.save_dataset("4",
  File "/data/gholl/checkouts/satpy/satpy/scene.py", line 1037, in save_dataset
    return writer.save_dataset(self[dataset_id],
  File "/data/gholl/checkouts/satpy/satpy/writers/ninjotiff.py", line 206, in save_dataset
    return super(NinjoTIFFWriter, self).save_dataset(
  File "/data/gholl/checkouts/satpy/satpy/writers/__init__.py", line 809, in save_dataset
    return self.save_image(img, filename=filename, compute=compute, fill_value=fill_value, **kwargs)
  File "/data/gholl/checkouts/satpy/satpy/writers/ninjotiff.py", line 178, in save_image
    return nt.save(img, filename, data_is_scaled_01=True, compute=compute, **kwargs)
  File "/data/gholl/checkouts/pyninjotiff/pyninjotiff/ninjotiff.py", line 560, in save
    return write(data, filename, area_def, ninjo_product_name, **kwargs)
  File "/data/gholl/checkouts/pyninjotiff/pyninjotiff/ninjotiff.py", line 665, in write
    ninjo_nav_parameters(options, area_def)
  File "/data/gholl/checkouts/pyninjotiff/pyninjotiff/ninjotiff.py", line 577, in ninjo_nav_parameters
    options.setdefault('projection', _get_projection_name(area_def))
  File "/data/gholl/checkouts/pyninjotiff/pyninjotiff/ninjotiff.py", line 289, in _get_projection_name
    return area_def.proj_id.split('_')[-1]
AttributeError: 'NoneType' object has no attribute 'split'

It seems that pyninjotiff wants to access the proj_id and expects it to be a str, and fails when this is instead None.

[djhoese]

This is an interesting error as this is the first case I've seen in "modern" code where proj_id is actually used for something. In pyresample 2.0 I think we had the idea to remove this attribute entirely.