fastiot.util.csv_reader module

class fastiot.util.csv_reader.CSVReader(filename, required_fields=None, optional_fields=None, checks=None, do_allow_arbitrary_fields=False)

A class for csv file reading. It uses python-lib’s csv package and does more strict checks on how the csv file must be formatted. Raises a CSVError if the file is incorrectly formatted.

Example usage:

with CSVReader(‘my_file.csv’,

required_fields=[‘my_field1’, ‘my_field2’], optional_fields=[‘my_optional_field2’]) as reader:

for data_row in reader:

print(data_row[‘my_field1’]) print(data_row[‘my_field2’]) print(data_row.get(‘my_optional_field2’, ‘unset’))

__init__(filename, required_fields=None, optional_fields=None, checks=None, do_allow_arbitrary_fields=False)

Constructor for csv reader.

Parameters:

• filename (str) – The filename of the csv file. Must be relative to workdir.

• required_fields (Optional[List[str]]) – Specify required field names which must be in the csv header line. If not, it will raise a CSVError during parsing.

• optional_fields (Optional[List[str]]) – Specify optional field names. If the csv file contains field names, which are not specified, it will raise a CSVError during parsing.

• checks (Optional[Dict[str, Callable[[str], bool]]]) – Specify checks for fields as a mapping of field names to callables. The callables should return true if a given value is valid, false otherwise.

• do_allow_arbitrary_fields (bool) – If true, it will consider all possible field names as optional. Use this option with caution because it will prevent possible errors from being detected.