Source code for safe.common.utilities
"""Utilities for InaSAFE
"""
import os
import gettext
from datetime import date
import getpass
from tempfile import mkstemp
from safe.common.exceptions import VerificationError
[docs]def verify(statement, message=None):
"""Verification of logical statement similar to assertions
Input
statement: expression
message: error message in case statement evaluates as False
Output
None
Raises
VerificationError in case statement evaluates to False
"""
if bool(statement) is False:
raise VerificationError(message)
[docs]def ugettext(s):
"""Translation support
"""
path = os.path.abspath(os.path.join(os.path.dirname(__file__),
'..', 'i18n'))
if 'LANG' not in os.environ:
return s
lang = os.environ['LANG']
filename_prefix = 'inasafe'
t = gettext.translation(filename_prefix,
path, languages=[lang], fallback=True)
return t.ugettext(s)
[docs]def temp_dir(sub_dir='work'):
"""Obtain the temporary working directory for the operating system.
An inasafe subdirectory will automatically be created under this and
if specified, a user subdirectory under that.
.. note:: You can use this together with unique_filename to create
a file in a temporary directory under the inasafe workspace. e.g.
tmpdir = temp_dir('testing')
tmpfile = unique_filename(dir=tmpdir)
print tmpfile
/tmp/inasafe/23-08-2012/timlinux/testing/tmpMRpF_C
Args:
sub_dir str - optional argument which will cause an additional
subirectory to be created e.g. /tmp/inasafe/foo/
Returns:
Path to the output clipped layer (placed in the system temp dir).
Raises:
Any errors from the underlying system calls.
"""
user = getpass.getuser().replace(' ', '_')
current_date = date.today()
date_string = current_date.strftime("%d-%m-%Y")
# Following 4 lines are a workaround for tempfile.tempdir() unreliabilty
handle, filename = mkstemp()
os.close(handle)
new_directory = os.path.dirname(filename)
os.remove(filename)
path = os.path.join(new_directory, 'inasafe', date_string, user, sub_dir)
if not os.path.exists(path):
# Ensure that the dir is world writable
# Umask sets the new mask and returns the old
old_mask = os.umask(0000)
os.makedirs(path, 0777)
# Resinstate the old mask for tmp
os.umask(old_mask)
return path
[docs]def unique_filename(**kwargs):
"""Create new filename guaranteed not to exist previously
Use mkstemp to create the file, then remove it and return the name
If dir is specified, the tempfile will be created in the path specified
otherwise the file will be created in a directory following this scheme:
:file:`/tmp/inasafe/<dd-mm-yyyy>/<user>/impacts'
See http://docs.python.org/library/tempfile.html for details.
Example usage:
tempdir = temp_dir(sub_dir='test')
filename = unique_filename(suffix='.keywords', dir=tempdir)
print filename
/tmp/inasafe/23-08-2012/timlinux/test/tmpyeO5VR.keywords
Or with no preferred subdir, a default subdir of 'impacts' is used:
filename = unique_filename(suffix='.shp')
print filename
/tmp/inasafe/23-08-2012/timlinux/impacts/tmpoOAmOi.shp
"""
if 'dir' not in kwargs:
path = temp_dir('impacts')
kwargs['dir'] = path
if not os.path.exists(kwargs['dir']):
# Ensure that the dir mask won't conflict with the mode
# Umask sets the new mask and returns the old
umask = os.umask(0000)
# Ensure that the dir is world writable by explictly setting mode
os.makedirs(kwargs['dir'], 0777)
# Reinstate the old mask for tmp dir
os.umask(umask)
# Now we have the working dir set up go on and return the filename
handle, filename = mkstemp(**kwargs)
# Need to close it using the filehandle first for windows!
os.close(handle)
try:
os.remove(filename)
except OSError:
pass
return filename
try:
from safe_qgis.utilities import getDefaults as get_qgis_defaults
def get_defaults(default=None):
return get_qgis_defaults(theDefault=default)
except ImportError:
#this is used when we are in safe without access to qgis (e.g. web )
from safe.defaults import DEFAULTS
def get_defaults(default=None):
if default is None:
return DEFAULTS
elif default in DEFAULTS:
return DEFAULTS[default]
else:
return None