class_docstr: Term binding to a numexpr expression.
  
  Parameters
  ----------
  expr : string
      A string suitable for passing to numexpr.  All variables in 'expr'
      should be of the form "x_i", where i is the index of the corresponding
      factor input in 'binds'.
  binds : tuple
      A tuple of factors to use as inputs.
  dtype : np.dtype
      The dtype for the expression.
class_docstr_tok: ["Term","binding","to","a","numexpr","expression",".","Parameters","--","--","--","--","--","expr",":","string","A","string","suitable","for","passing","to","numexpr",".","All","variables","in","'expr'","should","be","of","the","form","``","x_i","''",",","where","i","is","the","index","of","the","corresponding","factor","input","in","'binds","'",".","binds",":","tuple","A","tuple","of","factors","to","use","as","inputs",".","dtype",":","np.dtype","The","dtype","for","the","expression","."]
code: def _init(self, expr, *args, **kwargs):
      self._expr = expr
      return super(NumericalExpression, self)._init(*args, **kwargs)
  
imports: import re
  from itertools import chain
  from numbers import Number
  import numexpr
  from numexpr.necompiler import getExprNames
  from numpy import full, inf
  from zipline.pipeline.term import Term, ComputableTerm
  from zipline.utils.numpy_utils import bool_dtype
label_desc: Use image node_id 2 for calling the NumericalExpression obj's underlying member method code with example usage: obj._init(expr) and returns: super