[BUG] Iteration on `StringMethods` is resulting in infinite loop & hangs

[galipremsagar]

Describe the bug
StringMethods in pandas supports iteration and performing the same in cudf is resulting in infinite loops or hangs.

Steps/Code to reproduce bug

In [46]: import pandas as pd

In [47]: import cudf

In [48]: s = pd.Series(['a', 'b'])

In [49]: gs = cudf.from_pandas(s)

In [50]: for i in s.str:
    ...:     print(i)
    ...: 
<ipython-input-50-d888a34388a8>:1: FutureWarning: Columnar iteration over characters will be deprecated in future releases.
  for i in s.str:
0    a
1    b
dtype: object

In [51]: for i in gs.str:
    ...:     print(i)
    ...: 
.
.
.
.
Infinite loop

Expected behavior
Iteration should be disabled for all ColumnMethods since it is very inefficient.

Environment overview (please complete the following information)

• Environment location: [Bare-metal]
• Method of cuDF install: [from source]

[mroeschke]

Just a reminder to raise an exception in __iter__ specifically since I'm assuming __getitem__ is defined pandas-dev/pandas#54174

[galipremsagar]

Just a reminder to raise an exception in __iter__ specifically since I'm assuming __getitem__ is defined pandas-dev/pandas#54174

+1, yup that's the source of the issue.