def load_files(filenames, callback, constraints=None):
"""
Takes a list of filenames which may also be globs, and optionally a
constraint set and a callback function, and returns a
generator of Cubes from the given files.
.. note::
Typically, this function should not be called directly; instead, the
intended interface for loading is :func:`iris.load`.
"""
from iris.fileformats import FORMAT_AGENT
all_file_paths = expand_filespecs(filenames)
# Create default dict mapping iris format handler to its associated filenames
handler_map = collections.defaultdict(list)
for fn in all_file_paths:
with open(fn, "rb") as fh:
handling_format_spec = FORMAT_AGENT.get_spec(
os.path.basename(fn), fh)
handler_map[handling_format_spec].append(fn)
# Call each iris format handler with the approriate filenames
for handling_format_spec in sorted(handler_map):
fnames = handler_map[handling_format_spec]
if handling_format_spec.constraint_aware_handler:
for cube in handling_format_spec.handler(fnames, callback,
constraints):
yield cube
else:
for cube in handling_format_spec.handler(fnames, callback):
yield cube
def _structured_loader(fname):
with open(fname, 'rb') as fh:
spec = FORMAT_AGENT.get_spec(os.path.basename(fname), fh)
if spec.name.startswith(_FF_SPEC_NAME):
result = um_to_pp
elif spec.name.startswith(_PP_SPEC_NAME):
result = pp_load
else:
emsg = 'Require {!r} to be a structured FieldsFile or a PP file.'
raise ValueError(emsg.format(fname))
return result
def _structured_loader(fname):
with open(fname, 'rb') as fh:
spec = FORMAT_AGENT.get_spec(os.path.basename(fname), fh)
if spec.name.startswith(_FF_SPEC_NAME):
result = um_to_pp
elif spec.name.startswith(_PP_SPEC_NAME):
result = pp_load
else:
emsg = 'Require {!r} to be a structured FieldsFile or a PP file.'
raise ValueError(emsg.format(fname))
return result
def _select_raw_fields_loader(fname):
# Return the PPfield loading function for a file name.
#
# This decides whether the underlying file is an FF or PP file.
# Because it would be too awkward to modify the whole iris loading
# callchain to "pass down" the file format, this function instead
# 'recreates' that information by calling the format picker again.
# NOTE: this may be inefficient, especially for web resources.
from iris.fileformats import FORMAT_AGENT
from iris.fileformats.pp import load as pp_load
from iris.fileformats.um import um_to_pp
with open(fname, 'rb') as fh:
spec = FORMAT_AGENT.get_spec(os.path.basename(fname), fh)
if spec.name.startswith(_FF_SPEC_NAME):
loader = um_to_pp
elif spec.name.startswith(_PP_SPEC_NAME):
loader = pp_load
else:
emsg = 'Require {!r} to be a structured FieldsFile or a PP file.'
raise ValueError(emsg.format(fname))
return loader
def _select_raw_fields_loader(fname):
# Return the PPfield loading function for a file name.
#
# This decides whether the underlying file is an FF or PP file.
# Because it would be too awkward to modify the whole iris loading
# callchain to "pass down" the file format, this function instead
# 'recreates' that information by calling the format picker again.
# NOTE: this may be inefficient, especially for web resources.
from iris.fileformats import FORMAT_AGENT
from iris.fileformats.pp import load as pp_load
from iris.fileformats.um import um_to_pp
with open(fname, 'rb') as fh:
spec = FORMAT_AGENT.get_spec(os.path.basename(fname), fh)
if spec.name.startswith(_FF_SPEC_NAME):
loader = um_to_pp
elif spec.name.startswith(_PP_SPEC_NAME):
loader = pp_load
else:
emsg = 'Require {!r} to be a structured FieldsFile or a PP file.'
raise ValueError(emsg.format(fname))
return loader
def load_http(urls, callback):
"""
Takes a list of OPeNDAP URLs and a callback function, and returns a generator
of Cubes from the given URLs.
.. note::
Typically, this function should not be called directly; instead, the
intended interface for loading is :func:`iris.load`.
"""
# Create default dict mapping iris format handler to its associated filenames
from iris.fileformats import FORMAT_AGENT
handler_map = collections.defaultdict(list)
for url in urls:
handling_format_spec = FORMAT_AGENT.get_spec(url, None)
handler_map[handling_format_spec].append(url)
# Call each iris format handler with the appropriate filenames
for handling_format_spec in sorted(handler_map):
fnames = handler_map[handling_format_spec]
for cube in handling_format_spec.handler(fnames, callback):
yield cube
