numpy.fromregex#
- numpy.fromregex(file, regexp, dtype, encoding=None)[source]#
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:
- filefile, str, or pathlib.Path
Filename or file object to read.
Changed in version 1.22.0: Now accepts
os.PathLike
implementations.- regexpstr or regexp
Regular expression used to parse the file. Groups in the regular expression correspond to fields in the dtype.
- dtypedtype or list of dtypes
Dtype for the structured array; must be a structured datatype.
- encodingstr, optional
Encoding used to decode the inputfile. Does not apply to input streams.
New in version 1.14.0.
- Returns:
- outputndarray
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
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
>>> from io import StringIO >>> text = StringIO("1312 foo\n1534 bar\n444 qux")
>>> regexp = r"(\d+)\s+(...)" # match [digits, whitespace, anything] >>> output = np.fromregex(text, 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])