#
##
## SPDX-FileCopyrightText: © 2007-2023 Benedict Verhegghe <bverheg@gmail.com>
## SPDX-License-Identifier: GPL-3.0-or-later
##
## This file is part of pyFormex 3.4 (Thu Nov 16 18:07:39 CET 2023)
## pyFormex is a tool for generating, manipulating and transforming 3D
## geometrical models by sequences of mathematical operations.
## Home page: https://pyformex.org
## Project page: https://savannah.nongnu.org/projects/pyformex/
## Development: https://gitlab.com/bverheg/pyformex
## Distributed under the GNU General Public License version 3 or later.
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program. If not, see http://www.gnu.org/licenses/.
##
#
"""Numerical data reader
"""
__all__ = ['splitFloat', 'readData']
import re
_re_float = re.compile(r'[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?')
_re_float_string = re.compile(r'(?P<float>[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?)(?P<string>.*)')
[docs]def splitFloat(s):
"""Match a floating point number at the beginning of a string.
Parameters
----------
s: str
A string that starts with a numerical part (float).
Returns
-------
tuple (float, str) | None:
If the beginning of the string matches a floating point number,
returns a tuple with the float and the remainder of the string.
Else, return None
Examples
--------
>>> splitFloat('123e4rt345e6')
[1230000.0, 'rt345e6']
"""
m = _re_float_string.match(s)
if m:
return [float(m.group('float')), m.group('string')]
return None
[docs]def convertData(s, to):
"""Convert numerical data to a requested type or units.
Converts a string including a numerical value and optional units
to the requested type or units.
Parameters
----------
s: str
A string containing a numerical value and an optional units string,
optionally separated by whitespace. E.g. '10 kg'.
to: str
The units or type to which the value from the string ``s`` is to be
converted. If ``s`` contains units, the specified ``to`` units should
be compatible (i.e. for the same physical quantity).
If a field has no units, the target ``to`` value can also be
'int' or 'float'.
Returns
-------
int | float
The numerical value read from the string ``s``, converted to the
specified units or type ``to``.
Examples
--------
>>> convertData('1 inch', 'mm')
25.4
>>> convertData('1', 'mm')
1.0
>>> convertData('14.5e3', 'kg')
14500.0
>>> convertData('12 inch', 'float')
12.0
>>> convertData('17.5', 'int')
17
Warning
-------
You need to have the GNU ``units`` command installed for the unit
conversion to work.
"""
# IMPORT HERE: LATE IMPORT
from pyformex.plugins import units
s = s.strip()
m = _re_float.match(s)
if not m:
raise ValueError(f"No value found in '{s}'")
if m.end() == len(s) or to in ['int', 'float']:
# no units or no units conversion: handle ourself
val = float(s[:m.end()])
if to == 'int':
val = int(val)
else:
# let 'units' do the conversion
val = float(units.convertUnits(s, to))
return val
[docs]def readData(s, to, strict=False):
"""Read values from a string matching the units/type specifications.
This is a powerful function for reading, interpreting and converting
numerical data from a string.
Parameters
----------
s: str
A string containing comma-separated fields. Each field is either
a numerical value, or a numerical value followed by a units string.
The value and the units can optionally be separated by whitespace.
to: list of str
A list of units to which the fields in the string ``s`` should be
converted. The length of the list is usually equal to the number
of fields in the string ``s``.
If a field has units, the corresponding ``to`` should be a compatible
unit (i.e. for the same physical quantity). If a field has no units,
the target ``to`` value can also be 'int' or 'float'.
strict: bool
If True, the length of the ``to`` list should exactly match the
number of fields in ``s``. The default (False) allows unequal lengths
and will only proceed until the shortest is exhausted.
Returns
-------
list
A list of int/float values read from the string s.
With ``strict=True`` the list will have the same length as the
number of fields in ``s`` and the number of items in ``to``.
Else, it will have the shortest length of the two.
Where the field contains a units designator, the value is converted
to the requested ``to`` units.
designator.Fields in the string s are separated by
Examples
--------
>>> readData('1 inch', ['mm'])
[25.4]
>>> readData('12, 13s, 14.5e3, 12 inch, 1hr, 31kg, 5MPa',
... ['int','float','kg','cm','s','g','kN/m**2'])
[12, 13.0, 14500.0, 30.48, 3600.0, 31000.0, 5000.0]
Warning
-------
You need to have the GNU ``units`` command installed for the unit
conversion to work.
"""
data = s.split(',')
if strict and len(data) != len(to):
raise ValueError(f"'{s} does not match {to}")
return [convertData(si, ti) for ti, si in zip(to, data)]
# End
