def _evaluate(self):
import numexpr as ne
# convert the expression to a valid numexpr expression
s = self.convert()
try:
env = self.expr.env
scope = env.full_scope
truediv = scope["truediv"]
_check_ne_builtin_clash(self.expr)
return ne.evaluate(s, local_dict=scope, truediv=truediv)
except KeyError as e:
# python 3 compat kludge
try:
msg = e.message
except AttributeError:
msg = str(e)
raise UndefinedVariableError(msg)
def resolve(self, key: str, is_local: bool):
"""
Resolve a variable name in a possibly local context.
Parameters
----------
key : str
A variable name
is_local : bool
Flag indicating whether the variable is local or not (prefixed with
the '@' symbol)
Returns
-------
value : object
The value of a particular variable
"""
try:
# only look for locals in outer scope
if is_local:
return self.scope[key]
# not a local variable so check in resolvers if we have them
if self.has_resolvers:
return self.resolvers[key]
# if we're here that means that we have no locals and we also have
# no resolvers
assert not is_local and not self.has_resolvers
return self.scope[key]
except KeyError:
try:
# last ditch effort we look in temporaries
# these are created when parsing indexing expressions
# e.g., df[df > 0]
return self.temps[key]
except KeyError as err:
# runtime import because ops imports from scope
from pandas.core.computation.ops import UndefinedVariableError
raise UndefinedVariableError(key, is_local) from err