Basic string interpolation in pure python

gistfile1.py

# alike https://github.com/lihaoyi/macropy#string-interpolation

In [23]: class Interpol:
    def __getitem__(self, str):
        import inspect
        return str.format(**inspect.currentframe().f_back.f_locals)
   ....:     

In [24]: s = Interpol()

In [25]: a = 23

In [26]: b = 42

In [27]: s["Hail Eris! {a} {b}"]
Out[27]: 'Hail Eris! 23 42'