Tensorflow Fetch Operation Validation

validate_tensorflow_fetch_ops.py

import typing
import tensorflow as tf


def validate_fetch(fetch_ops: typing.Union[str, list, dict, tf.Tensor]):
    if isinstance(fetch_ops, str):
        if not len(fetch_ops) > 0:
            raise Exception("Fetch Op is an empty string")
        return fetch_ops
    elif isinstance(fetch_ops, tf.Tensor):
        return fetch_ops
    elif isinstance(fetch_ops, list):
        if len(fetch_ops) == 0:
            raise Exception(
                "Fetch operations is an empty list. Requires a list of str of Tensors. Given, fetch_ops: {}".format(
                    fetch_ops))
        for fetch_op in fetch_ops:
            validate_fetch(fetch_op)
        return fetch_ops
    elif isinstance(fetch_ops, dict):
        if len(fetch_ops) == 0:
            raise Exception("Fetch operations is an empty list. fetch_ops: {}".format(fetch_ops))
        for k, v in fetch_ops.items():
            if not isinstance(k, str) or len(k) == 0:
                raise Exception(
                    'Key of Fetch Ops should be a string and len(key) should be > 0. Given, type:{}, value:{}'.format(type(k),k))
            validate_fetch(v)
        return fetch_ops
    else:
        raise Exception('Fetch Ops support one among [str, list, dict, tf.Tensor]. Given: {}'.format(type(fetch_ops)))


ops_false = (
    '',
    None,
    [],
    [[]],
    ['123', []],
    {},
    {1:2},
    {'':3},
    {'123':3},
    {'123':[]},
    {'123':[[123]]},
    {'123':{}},

)


ops_true = (
    'abc',
    ['123'],
    [['123'], [[[[[[[[[['123']]]]]]]]]]],
    {'123':'123'},
    {'123':[['123']]},

)

print(validate_fetch(ops_true[0]))