Class NameValidator

numpy/lib/_iotools.py:229–383

Object to validate a list of strings to use as field names. The strings are stripped of any non alphanumeric character, and spaces are replaced by '_'. During instantiation, the user can define a list of names to exclude, as well as a list of invalid characters. Names in the ex

class NameValidator:
    """
    Object to validate a list of strings to use as field names.

    The strings are stripped of any non alphanumeric character, and spaces
    are replaced by '_'. During instantiation, the user can define a list
    of names to exclude, as well as a list of invalid characters. Names in
    the exclusion list are appended a '_' character.

    Once an instance has been created, it can be called with a list of
    names, and a list of valid names will be created.  The `__call__`
    method accepts an optional keyword "default" that sets the default name
    in case of ambiguity. By default this is 'f', so that names will
    default to `f0`, `f1`, etc.

    Parameters
    ----------
    excludelist : sequence, optional
        A list of names to exclude. This list is appended to the default
        list ['return', 'file', 'print']. Excluded names are appended an
        underscore: for example, `file` becomes `file_` if supplied.
    deletechars : str, optional
        A string combining invalid characters that must be deleted from the
        names.
    case_sensitive : {True, False, 'upper', 'lower'}, optional
        * If True, field names are case-sensitive.
        * If False or 'upper', field names are converted to upper case.
        * If 'lower', field names are converted to lower case.

        The default value is True.
    replace_space : '_', optional
        Character(s) used in replacement of white spaces.

    Notes
    -----
    Calling an instance of `NameValidator` is the same as calling its
    method `validate`.

    Examples
    --------
    >>> import numpy as np
    >>> validator = np.lib._iotools.NameValidator()
    >>> validator(['file', 'field2', 'with space', 'CaSe'])
    ('file_', 'field2', 'with_space', 'CaSe')

    >>> validator = np.lib._iotools.NameValidator(excludelist=['excl'],
    ...                                           deletechars='q',
    ...                                           case_sensitive=False)
    >>> validator(['excl', 'field2', 'no_q', 'with space', 'CaSe'])
    ('EXCL', 'FIELD2', 'NO_Q', 'WITH_SPACE', 'CASE')

    """

    defaultexcludelist = 'return', 'file', 'print'
    defaultdeletechars = frozenset(r"""~!@#$%^&*()-=+~\|]}[{';: /?.>,<""")

    def __init__(self, excludelist=None, deletechars=None,
                 case_sensitive=None, replace_space='_'):