[Bug] Unusable parameters in Python API

[pesekon2]

Describe the bug

Parameter names of some modules written in C (r.resamp.bspline, r.walk, v.outlier) can stand for statements (exempli gratia, lambda) in Python, making it impossible to use them through the Python API.

EDIT: The same applies to Python module r.fillnulls (handled later in the code by using lambda_ = float(options["lambda"]))

To Reproduce

Using the basic NC dataset.

In:

#!/usr/bin/env python3

from grass.pygrass.modules import Module

def main():
    Module('g.region', raster='elevation')
    rules = """
    1:3:0.1:0.1
    4:5:10.:10.
    6:6:1000.0:1000.0
    7:7:0.3:0.3
    """
    Module(
        'r.recode',
        input='landuse@PERMANENT',
        output='friction',
        rules='-',
        stdin_=rules,
        overwrite=True
    )
    Module(
        'r.walk',
        flags='k',
        elevation='elevation@PERMANENT',
        friction='friction',
        output='walkcost',
        outdir='walkdir',
        start_coordinates=[635000, 220000],
        lambda=0.5,
        max_cost=10000,
        overwrite=True
    )

if __name__ == '__main__':
    main()

Out:

  File "/tmp/test.py", line 33
    lambda=0.5,
    ^^^^^^
SyntaxError: invalid syntax

Expected behavior

Work.

System description:

• Operating System: Debian bookworm, Windows 8
• GRASS GIS version: trunk, 8.2.0

Possible fixes

1. Avoid parameter names such as lambda + rename the current parameter
2. Something smart that would deal with the current modules without breaking their API consistency (I do not know about any such way myself)

Current workaround

Use **kwargs:

```python
#!/usr/bin/env python3

from grass.pygrass.modules import Module

def main():
    Module('g.region', raster='elevation')
    rules = """
    1:3:0.1:0.1
    4:5:10.:10.
    6:6:1000.0:1000.0
    7:7:0.3:0.3
    """
    Module(
        'r.recode',
        input='landuse@PERMANENT',
        output='friction',
        rules='-',
        stdin_=rules,
        overwrite=True
    )

    kwargs = {'lambda': 0.5}

    Module(
        'r.walk',
        flags='k',
        elevation='elevation@PERMANENT',
        friction='friction',
        output='walkcost',
        outdir='walkdir',
        start_coordinates=[635000, 220000],
        max_cost=10000,
        overwrite=True,
        **kwargs
    )

if __name__ == '__main__':
    main()

[ninsbl]

Did you try lambda_?

[pesekon2]

I thought I did. But apparently, I did something wrong (a typo, probably), because it works now. Thank you.

I'm adding the invalid label and closing the issue.