flopscope.numpy.fromregex

flopscope.numpy.fromregex(file, regexp, dtype, encoding=None)[flopscope 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

file:file, str, or pathlib.Path: Filename or file object to read.
Changed in version 1.22.0.
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; must be a structured datatype.
encoding:str, optional: Encoding used to decode the inputfile. Does not apply to input streams.

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.

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

>>> import flopscope.numpy as fnp
>>> from io import StringIO
>>> text = StringIO("1312 foo\n1534  bar\n444   qux")

>>> regexp = r"(\d+)\s+(...)"  # match [digits, whitespace, anything]
>>> output = flops.fromregex(text, regexp,
... [('num', flops.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])