def load(self, channels=None, load_again=False, area_extent=None, **kwargs):
"""Load instrument data into the *channels*. *Channels* is a list or a
tuple containing channels we will load data into, designated by there
center wavelength (float), resolution (integer) or name (string). If
None, all channels are loaded.
The *load_again* boolean flag allows to reload the channels even they
have already been loaded, to mirror changes on disk for example. This
is false by default.
The *area_extent* keyword lets you specify which part of the data to
load. Given as a 4-element sequence, it defines the area extent to load
in satellite projection.
The other keyword arguments are passed as is to the reader
plugin. Check the corresponding documentation for more details.
"""
# Set up the list of channels to load.
if channels is None:
for chn in self.channels:
self.channels_to_load |= set([chn.name])
elif(isinstance(channels, (list, tuple, set))):
for chn in channels:
try:
self.channels_to_load |= set([self[chn].name])
except KeyError:
self.channels_to_load |= set([chn])
else:
raise TypeError("Channels must be a list/"
"tuple/set of channel keys!")
loaded_channels = [chn.name for chn in self.loaded_channels()]
if load_again:
for chn in self.channels_to_load:
if chn in loaded_channels:
self.unload(chn)
loaded_channels = []
else:
for chn in loaded_channels:
self.channels_to_load -= set([chn])
# find the plugin to use from the config file
conf = ConfigParser.ConfigParser()
try:
conf.read(os.path.join(CONFIG_PATH, self.fullname + ".cfg"))
if len(conf.sections()) == 0:
raise ConfigParser.NoSectionError(("Config file did "
"not make sense"))
levels = [section for section in conf.sections()
if section.startswith(self.instrument_name+"-level")]
except ConfigParser.NoSectionError:
LOG.warning("Can't load data, no config file for " + self.fullname)
self.channels_to_load = set()
return
levels.sort()
if levels[0] == self.instrument_name+"-level1":
levels = levels[1:]
if len(levels) == 0:
raise ConfigParser.NoSectionError(
self.instrument_name+"-levelN (N>1) to tell me how to"+
" read data... Not reading anything.")
for level in levels:
if len(self.channels_to_load) == 0:
return
LOG.debug("Looking for sources in section "+level)
reader_name = conf.get(level, 'format')
try:
reader_name = eval(reader_name)
except NameError:
reader_name = str(reader_name)
LOG.debug("Using plugin mpop.satin."+reader_name)
# read the data
reader = "mpop.satin."+reader_name
try:
try:
# Look for builtin reader
reader_module = __import__(reader, globals(),
locals(), ['load'])
except ImportError:
# Look for custom reader
reader_module = __import__(reader_name, globals(),
locals(), ['load'])
if area_extent is not None:
if(isinstance(area_extent, (tuple, list)) and
len(area_extent) == 4):
kwargs["area_extent"] = area_extent
else:
raise ValueError("Area extent must be a sequence of "
"four numbers.")
reader_module.load(self, **kwargs)
except ImportError:
LOG.exception("ImportError while loading "+reader+".")
continue
loaded_channels = [chn.name for chn in self.loaded_channels()]
self.channels_to_load = set([chn for chn in self.channels_to_load
if not chn in loaded_channels])
LOG.debug("Successfully loaded: "+str(loaded_channels))
if len(self.channels_to_load) > 0:
LOG.warning("Unable to import channels "
+ str(self.channels_to_load))
self.channels_to_load = set()
