Module « numpy.matlib »

Fonction fromregex - module numpy.matlib

Signature de la fonction fromregex

def fromregex(file, regexp, dtype, encoding=None) 

Description

fromregex.__doc__

    Construct an array from a text file, using regular expression parsing.

    The returned array is always a structured array, and is constructed from
    all matches of the regular expression in the file. Groups in the regular
    expression are converted to fields of the structured array.

    Parameters
    ----------
    file : str or file
        Filename or file object to read.
    regexp : str or regexp
        Regular expression used to parse the file.
        Groups in the regular expression correspond to fields in the dtype.
    dtype : dtype or list of dtypes
        Dtype for the structured array.
    encoding : str, optional
        Encoding used to decode the inputfile. Does not apply to input streams.

        .. versionadded:: 1.14.0

    Returns
    -------
    output : ndarray
        The output array, containing the part of the content of `file` that
        was matched by `regexp`. `output` is always a structured array.

    Raises
    ------
    TypeError
        When `dtype` is not a valid dtype for a structured array.

    See Also
    --------
    fromstring, loadtxt

    Notes
    -----
    Dtypes for structured arrays can be specified in several forms, but all
    forms specify at least the data type and field name. For details see
    `basics.rec`.

    Examples
    --------
    >>> f = open('test.dat', 'w')
    >>> _ = f.write("1312 foo\n1534  bar\n444   qux")
    >>> f.close()

    >>> regexp = r"(\d+)\s+(...)"  # match [digits, whitespace, anything]
    >>> output = np.fromregex('test.dat', regexp,
    ...                       [('num', np.int64), ('key', 'S3')])
    >>> output
    array([(1312, b'foo'), (1534, b'bar'), ( 444, b'qux')],
          dtype=[('num', '<i8'), ('key', 'S3')])
    >>> output['num']
    array([1312, 1534,  444])