how to use a loop with pytest.mark.parametrize() ?

[maphew]

Hi, I'm new to pytest and fumbling my way about. I'm hoping someone has the time to point me in the right direction.

This works:

# x results in string 'gdalcompare'
# responses is a list: ['Usage: gdalcompare.py [-sds] <golden_file> <new_file>\n', '']

x = utils[12]   
@pytest.mark.parametrize("input,want", [
    pytest.param(x, {
        "stdout": responses[x][0],
        "stderr": responses[x][1],
    })
])

But how can I now build on this so that x is fed with a loop? The following naive attempt fails with "IndentationError: unexpected unindent" or syntax error depending on how I play with various formatting.

for x in utils:
    @pytest.mark.parametrize("input,want", [
        pytest.param(x, {
            "stdout": responses[x][0],
            "stderr": responses[x][1],
        })
    ])

Full script is at https://github.com/maphew/gdal/blob/pr-5281-redux/autotest/pyscripts/test_gdal_utils_cli.py. Note: this file and it's data files are the only ones written by me. Everything else is from others with more experience. I've been asking them enough for other help so I'm trying to spread things around.

Thanks in advance for any attention you may spend on this.

[nicoddemus]

Hi @maphew,

The answer is to build the list of possible pytest.param values and pass that on to pytest.mark.parametrize:

params = [
    pytest.param(x, {
        "stdout": responses[x][0],
        "stderr": responses[x][1],
    })
    for x in utils
]    

@pytest.mark.parametrize("input,want", params)
def test_program(input, want):
    ...

[maphew]

Thank you @nicoddemus!

[parkitny]

very useful. Thanks!