msg_native example

[jakeri]

Can someone write a small example on how to use the msg_native driver?

I tried:
global_scene = Scene(filenames="MSG1-SEVI-MSG15-0201-NA-20080131234240.880000000Z-20110506121050-1224354-2.nat", platform_name="Meteosat-10", sensor="seviri", reader="native_msg",base_dir="/mnt/LC3950L4/")

But I guess it is related to the
file_patterns: ['{satid:4s}-{instr:4s}-MSG{product_level:2d}-0100-NA-{processing_time1:%Y%m%d%H%M%S.%f}000Z-{processing_time2:%Y%m%d%H%M%S}-{order_id:d}.nat']

Can I override this id somehow and just send in the file?

[djhoese]

filenames must be passed as a list to the Scene creation. Try adding [ and ] round your filename string.

[ghost]

I tried that too. Should it be possible to specify a full file path?

I would like to skip file_patterns-handling when using nat files. If possible.

>>> import os
>>> from satpy import Scene
>>> from datetime import datetime
>>> from satpy.utils import debug_on
>>> 
>>> debug_on()
>>> global_scene = Scene(filenames=["/mnt/LC3950L4/MSG1-SEVI-MSG15-0201-NA-20080131234240.880000000Z-20110506121050-1224354-2.nat"], platform_name="Meteosat-10", sensor="seviri", reader="native_msg")
[DEBUG: 2017-09-02 19:56:35 : satpy.scene] Setting 'PPP_CONFIG_DIR' to '/usr/local/lib/python2.7/dist-packages/satpy/etc'
[DEBUG: 2017-09-02 19:56:35 : satpy.readers] Reading ['/usr/local/lib/python2.7/dist-packages/satpy/etc/readers/native_msg.yaml', '/usr/local/lib/python2.7/dist-packages/satpy/etc/readers/native_msg.yaml', '/usr/local/lib/python2.7/dist-packages/satpy/etc/readers/native_msg.yaml']
[WARNING: 2017-09-02 19:56:35 : satpy.readers.yaml_reader] No filenames found for reader: native_msg
[WARNING: 2017-09-02 19:56:35 : satpy.readers] Don't know how to open the following files: set(['/mnt/LC3950L4/MSG1-SEVI-MSG15-0201-NA-20080131234240.880000000Z-20110506121050-1224354-2.nat'])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/satpy/scene.py", line 102, in __init__
    metadata=metadata)
  File "/usr/local/lib/python2.7/dist-packages/satpy/scene.py", line 150, in create_reader_instances
    metadata=metadata)
  File "/usr/local/lib/python2.7/dist-packages/satpy/readers/__init__.py", line 357, in __call__
    raise ValueError("No supported files found")
ValueError: No supported files found

[ghost]

Found that problem. Found out the problem with the default file_pattern. I had MSG1-SEVI-MSG15-0201-NA-20080131234240.880000000Z-20110506121050-1224354-2.nat but the globify-pattern dictated ????-????-MSG??-0100-NA-??????????????.*000Z-??????????????-*.nat, i.e 0100 vs 0201.

And now next problem. :-)

AttributeError: 'NativeMSGFileHandler' object has no attribute 'metadata'

>>> global_scene = Scene(filenames=["MSG1-SEVI-MSG15-0201-NA-20080131234240.880000000Z-20110506121050-1224354-2.nat"], platform_name="Meteosat-10", sensor="seviri", reader="native_msg")
[DEBUG: 2017-09-02 20:21:10 : satpy.scene] Setting 'PPP_CONFIG_DIR' to '/mnt/pytroll/satpy-config/'
[DEBUG: 2017-09-02 20:21:10 : satpy.readers] Reading ['/usr/local/lib/python2.7/dist-packages/satpy/etc/readers/native_msg.yaml', '/mnt/pytroll/satpy-config/readers/native_msg.yaml', '/mnt/pytroll/satpy-config/readers/native_msg.yaml']
[DEBUG: 2017-09-02 20:21:10 : satpy.readers.yaml_reader] Assigning to native_msg: ['MSG1-SEVI-MSG15-0201-NA-20080131234240.880000000Z-20110506121050-1224354-2.nat']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/satpy/scene.py", line 102, in __init__
    metadata=metadata)
  File "/usr/local/lib/python2.7/dist-packages/satpy/scene.py", line 150, in create_reader_instances
    metadata=metadata)
  File "/usr/local/lib/python2.7/dist-packages/satpy/readers/__init__.py", line 340, in __call__
    reader_instance.create_filehandlers(loadables)
  File "/usr/local/lib/python2.7/dist-packages/satpy/readers/yaml_reader.py", line 594, in create_filehandlers
    filename_set)
  File "/usr/local/lib/python2.7/dist-packages/satpy/readers/yaml_reader.py", line 583, in new_filehandlers_for_filetype
    return list(filtered_iter)
  File "/usr/local/lib/python2.7/dist-packages/satpy/readers/yaml_reader.py", line 545, in filter_fh_by_area
    for filehandler in filehandlers:
  File "/usr/local/lib/python2.7/dist-packages/satpy/readers/yaml_reader.py", line 513, in filter_fh_by_time
    for filehandler in filehandlers:
  File "/usr/local/lib/python2.7/dist-packages/satpy/readers/yaml_reader.py", line 557, in filter_fh_by_metadata
    if (key in filehandler.metadata and
AttributeError: 'NativeMSGFileHandler' object has no attribute 'metadata'

[jakeri]

After looking at the code, I think there is a bug in 0.7.1. I reverted back to 0.7.0 and msg_native worked fine. It seems to be related to metadata handling in reader.

[djhoese]

Good find @jakeri. This is probably a bug from @mraspaud's recent pull request: #58

[djhoese]

@mraspaud Could you test this if you have the time?

[mraspaud]

I don't get this error in the feature-xarray branch

[sjoro]

Fixed and merged to develop