r""" 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.
(file, regexp, dtype, encoding=None)
| 1637 | |
| 1638 | @set_module('numpy') |
| 1639 | def fromregex(file, regexp, dtype, encoding=None): |
| 1640 | r""" |
| 1641 | Construct an array from a text file, using regular expression parsing. |
| 1642 | |
| 1643 | The returned array is always a structured array, and is constructed from |
| 1644 | all matches of the regular expression in the file. Groups in the regular |
| 1645 | expression are converted to fields of the structured array. |
| 1646 | |
| 1647 | Parameters |
| 1648 | ---------- |
| 1649 | file : path or file |
| 1650 | Filename or file object to read. |
| 1651 | |
| 1652 | .. versionchanged:: 1.22.0 |
| 1653 | Now accepts `os.PathLike` implementations. |
| 1654 | regexp : str or regexp |
| 1655 | Regular expression used to parse the file. |
| 1656 | Groups in the regular expression correspond to fields in the dtype. |
| 1657 | dtype : dtype or list of dtypes |
| 1658 | Dtype for the structured array; must be a structured datatype. |
| 1659 | encoding : str, optional |
| 1660 | Encoding used to decode the inputfile. Does not apply to input streams. |
| 1661 | |
| 1662 | .. versionadded:: 1.14.0 |
| 1663 | |
| 1664 | Returns |
| 1665 | ------- |
| 1666 | output : ndarray |
| 1667 | The output array, containing the part of the content of `file` that |
| 1668 | was matched by `regexp`. `output` is always a structured array. |
| 1669 | |
| 1670 | Raises |
| 1671 | ------ |
| 1672 | TypeError |
| 1673 | When `dtype` is not a valid dtype for a structured array. |
| 1674 | |
| 1675 | See Also |
| 1676 | -------- |
| 1677 | fromstring, loadtxt |
| 1678 | |
| 1679 | Notes |
| 1680 | ----- |
| 1681 | Dtypes for structured arrays can be specified in several forms, but all |
| 1682 | forms specify at least the data type and field name. For details see |
| 1683 | `basics.rec`. |
| 1684 | |
| 1685 | Examples |
| 1686 | -------- |
| 1687 | >>> from io import StringIO |
| 1688 | >>> text = StringIO("1312 foo\n1534 bar\n444 qux") |
| 1689 | |
| 1690 | >>> regexp = r"(\d+)\s+(...)" # match [digits, whitespace, anything] |
| 1691 | >>> output = np.fromregex(text, regexp, |
| 1692 | ... [('num', np.int64), ('key', 'S3')]) |
| 1693 | >>> output |
| 1694 | array([(1312, b'foo'), (1534, b'bar'), ( 444, b'qux')], |
| 1695 | dtype=[('num', '<i8'), ('key', 'S3')]) |
| 1696 | >>> output['num'] |