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# numpy.fromregex

`numpy.``fromregex`(file, regexp, dtype)

  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 File name 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.
  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 `doc.structured_arrays`.

  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([(1312L, 'foo'), (1534L, 'bar'), (444L, 'qux')],
            dtype=[('num', '<i8'), ('key', '|S3')])
      >>> output['num']
      array([1312, 1534,  444], dtype=int64)

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