TypeError: float() argument must be a string or a number, not 'NoneType' when using experimental_python_types=True

[wolfgangcolsman]

Expected behavior

None values are mapped to None in _array_map_func

E.g

    def _array_map_func(self, column):
        element_mapping_func = self._col_func(column['arguments'][0]['value'])
        return lambda values: [element_mapping_func(value) if value is not None else None for value in values]

Actual behavior

None in arrays cause TypeError: float() argument must be a string or a number, not 'NoneType'

Steps To Reproduce

query a real array column containing a mix of None and real values

Log output

  File "/usr/local/lib/python3.9/site-packages/trino/dbapi.py", line 435, in execute
    result = self._query.execute()
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 758, in execute
    self._result.rows += self.fetch()
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 782, in fetch
    return self._row_mapper.map(status.rows)
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 982, in map
    return [self._map_row(row) for row in rows]
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 982, in <listcomp>
    return [self._map_row(row) for row in rows]
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 985, in _map_row
    return [self._map_value(value, self.columns[idx]) for idx, value in enumerate(row)]
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 985, in <listcomp>
    return [self._map_value(value, self.columns[idx]) for idx, value in enumerate(row)]
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 992, in _map_value
    return col_mapping_func(value)
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 892, in <lambda>
    return lambda values: [element_mapping_func(value) for value in values]
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 892, in <listcomp>
    return lambda values: [element_mapping_func(value) for value in values]
  File "/usr/local/lib/python3.9/site-packages/trino/client.py", line 907, in <lambda>
    else float(val)
TypeError: float() argument must be a string or a number, not 'NoneType'

Operating System

Bullseye

Trino Python client version

trino-0.318.0

Trino Server version

367

Python version

3.9

Are you willing to submit PR?

• Yes I am willing to submit a PR!