[Python] How to cast JSON String Array to STRUCT in arrow?

[Priyam Roy]

I have an array, for example:

>>> arr = pa.array(["[{'key': 1}]", None, None])

When I do -
>>> arr.cast(pa.list_(pa.struct([('key', pa.int64())])))

I get this traceback:
File "pyarrow/_compute.pyx", line 572, in pyarrow._compute.call_function
  File "pyarrow/_compute.pyx", line 367, in pyarrow._compute.Function.call
  File "pyarrow/error.pxi", line 144, in
pyarrow.lib.pyarrow_internal_check_status
  File "pyarrow/error.pxi", line 121, in pyarrow.lib.check_status
pyarrow.lib.ArrowNotImplementedError: Unsupported cast from string to list
using function cast_list

Any idea how can I get it happen please?