def preprocess(string, environ=None):
"""
Preprocesses a string, by replacing `${VARNAME}` with
`os.environ['VARNAME']` and ~ with the path to the user's
home directory
Parameters
----------
string : str
String object to preprocess
environ : dict, optional
If supplied, preferentially accept values from
this dictionary as well as `os.environ`. That is,
if a key appears in both, this dictionary takes
precedence.
Returns
-------
rval : str
The preprocessed string
"""
if environ is None:
environ = {}
split = string.split('${')
rval = [split[0]]
for candidate in split[1:]:
subsplit = candidate.split('}')
if len(subsplit) < 2:
raise ValueError('Open ${ not followed by } before '
'end of string or next ${ in "' + string + '"')
varname = subsplit[0]
try:
val = (environ[varname] if varname in environ
else os.environ[varname])
except KeyError:
if varname == 'PYLEARN2_DATA_PATH':
reraise_as(NoDataPathError())
if varname == 'PYLEARN2_VIEWER_COMMAND':
reraise_as(EnvironmentVariableError(
viewer_command_error_essay + environment_variable_essay)
)
reraise_as(ValueError('Unrecognized environment variable "' +
varname + '". Did you mean ' +
match(varname, os.environ.keys()) + '?'))
rval.append(val)
rval.append('}'.join(subsplit[1:]))
rval = ''.join(rval)
string = os.path.expanduser(string)
return rval
def preprocess(string):
"""
Preprocesses a string, by replacing `${VARNAME}` with
`os.environ['VARNAME']`
Parameters
----------
string : str
String object to preprocess
Returns
-------
rval : str
The preprocessed string
"""
split = string.split('${')
rval = [split[0]]
for candidate in split[1:]:
subsplit = candidate.split('}')
if len(subsplit) < 2:
raise ValueError('Open ${ not followed by } before ' \
+ 'end of string or next ${ in "' \
+ string + '"')
varname = subsplit[0]
if varname == 'PYLEARN2_TRAIN_FILE_NAME':
warnings.warn(
"PYLEARN2_TRAIN_FILE_NAME is deprecated and may be "
"removed from the library on or after Oct 22, 2013. Switch"
" to PYLEARN2_TRAIN_FILE_FULL_STEM")
try:
val = os.environ[varname]
except KeyError:
if varname == 'PYLEARN2_DATA_PATH':
raise NoDataPathError()
if varname == 'PYLEARN2_VIEWER_COMMAND':
raise EnvironmentVariableError(environment_variable_essay)
raise ValueError('Unrecognized environment variable "' + varname +
'". Did you mean ' +
match(varname, os.environ.keys()) + '?')
rval.append(val)
rval.append('}'.join(subsplit[1:]))
rval = ''.join(rval)
return rval