code: def Q(name):
      
      env = EvalEnvironment.capture(1)
      try:
          return env.namespace[name]
      except KeyError:
          raise NameError("No data named {!r} found".format(name))
docs: Quote a variable name
  
      A way to 'quote' variable names, especially ones that do not otherwise
      meet Python's variable name rules.
  
      Parameters
      ----------
      name : str
          Name of variable
  
      Returns
      -------
      value : object
          Value of variable
  
      Examples
      --------
      >>> import pandas as pd
      >>> from plydata import define
      >>> df = pd.DataFrame({'class': [10, 20, 30]})
  
      Since ``class`` is a reserved python keyword it cannot be a variable
      name, and therefore cannot be used in an expression without quoting it.
  
      >>> df >> define(y='class+1')
      Traceback (most recent call last):
        File "<string>", line 1
          class+1
              ^
      SyntaxError: invalid syntax
  
      >>> df >> define(y='Q("class")+1')
         class   y
      0     10  11
      1     20  21
      2     30  31
  
      Note that it is ``'Q("some name")'`` and not ``'Q(some name)'``.
      As in the above example, you do not need to ``import`` ``Q`` before
      you can use it.