issue_comments

wow! that's awesome! thanks so much, @simonw!

This won't be in a release for a little while, but you can install it to try it out using:

pip install https://github.com/simonw/sqlite-utils/archive/ee13f98c2c.zip

OK, this is implemented. Updated documentation is here: https://sqlite-utils.datasette.io/en/latest/cli.html#converting-data-in-columns

I think the fix for this is to change the rules about what code is accepted in both the - mode and the literal code string mode: you can pass in a Python expression, OR a fragment that gets turned into a function, OR code that implements its own def convert(value) function. So this would work too: sh sqlite-utils convert my.db mytable col1 ' def convert(value): return value.upper() '

My first attempt at building this looked a little bit strange, because you would end up having a file like this convert.py:

value = value.upper() return value Which gets used like this:

cat convert.py | sqlite-utils convert my.db mytable col1 -

But... that convert.py code isn't actually valid Python - it's a weird thing where you have a partial snippet of Python code that gets wrapped in a function automatically.

It would be better if you could write convert.py as a valid Python file with a function in it, something like this: python def convert(value): value = value.upper() return value

One option: allow CODE to be a special value of - which means "read from standard input". It's a tiny bit of a hack but I think it would work here.

If you wanted to replace a column entirely with hyphens you would still be able to do this:

sqlite-utils convert my.db mytable col1 '"-"'

One challenge here: the current signature looks like this: % sqlite-utils convert --help Usage: sqlite-utils convert [OPTIONS] DB_PATH TABLE COLUMNS... CODE CODE is a positional argument which comes last - and since COLUMNS can be one or more items, making CODE optional isn't easy.

There's a very non-obvious workaround for this at the moment. You can save your code in e.g. a file calledtransform.py - my test one looks like this: python def upper(value): return value.upper() Then you can run the following to import and use that function:

PYTHONPATH=. sqlite-utils convert fixtures.db roadside_attractions name 'transform.upper(value)' --import transform

That PYTHONPATH=. bit is necessary because otherwise the script won't look in the current directory for thattransform.py` module.

Now that I've written this down, it's obviously bad! I think your suggestion here is a good idea.