def __new__(cls, name, expr, replace=False):
# code
efound = expr in [
Variable.variables[key].expr for key in Variable.variables
]
if efound:
key = [
key for key in Variable.variables
if expr in Variable.variables[key].expr
]
logger.info("Expression '%s' already exists for key %s", expr, key)
return
else:
if replace or not name in Variable.variables:
if not valid_name(name):
logger.info("Invalid variable key: %s", name)
return
try:
result = parser.expr(expr)
except:
logger.info("Invalid expression: %s", expr)
return
return super(Variable, cls).__new__(cls)
else:
logger.info("Key %s already exists", name)
def vwalk(allv, vname):
vxlag, root, plist, lag = vparse(vname)
if root in Variable.variables:
root_expr = Variable.variables[root].expr
expr = vsub(vname, root_expr)
av = allvars(expr)
for v in av:
vwalk(allv, v)
else:
for p in plist:
if valid_name(p):
vwalk(allv, p)
allv.append(vname)
return allv
def allvars(expr):
r"""Get the list of valid names in the expression.
Parameters
----------
expr : str
A valid expression conforming to the Variable Definition Language.
Returns
-------
vlist : list
List of valid variable names.
"""
regex = re.compile('\w+')
items = regex.findall(expr)
vlist = []
for item in items:
if valid_name(item):
vlist.append(item)
return vlist