feat: add DataFrame.iter_rows

[Priyansh121096]

What type of PR is this? (check all applicable)

• [ ] 💾 Refactor
• [x] ✨ Feature
• [ ] 🐛 Bug Fix
• [ ] 🔧 Optimization
• [ ] 📝 Documentation
• [ ] ✅ Test
• [ ] 🐳 Other

Related issues

• Related issue #
• Closes #285

Checklist

• [x] Code follows style guide (ruff)
• [x] Tests added
• [x] Documented the changes

If you have comments or can explain your changes, please do so below.

I've matched the API with https://docs.pola.rs/api/python/stable/reference/dataframe/api/polars.DataFrame.rows.html

[Priyansh121096]

Thanks for your comments. I'll address them soon.

[Priyansh121096]

Just got a question about this functionality - instead of DataFrame.rows, couldn't we just add DataFrame.iter_rows?

@MarcoGorelli I was going to propose something similar (you beat me to it 😄). I was thinking we could expose both rows and iter_rows since the polars API does as well.

One issue with this one is I'm not sure if pandas has a convenient equivalent to this when named=True. Rest of the cases are fine:

1. polars + named=False = df.iter_rows(named=False)
2. polars + named=True = df.iter_rows(named=True)
3. pandas + named=False = df.itertuples(index=False, name=None)
4. pandas + named=True = ?

Please let me know if you're aware of a pandas API which returns an iterator for iterating over rows as dictionaries.

[FBruzzesi]

@Priyansh121096 I tried to play with the into argument of .to_dict() method, sadly with no success.

I guess that 4. can become iter(df.to_dict("records"))?!

[MarcoGorelli]

How about using https://docs.python.org/3/library/collections.html#collections.somenamedtuple._asdict (which , despite the underscore, is public):

something like (simplified)

def iter_rows(df):
    yield from (row._asdict() for row in df.itertuples(index=False))

[Priyansh121096]

I guess that 4. can become iter(df.to_dict("records"))?!

I feel like this defeats the purpose of using iter_rows over rows though.

How about using https://docs.python.org/3/library/collections.html#collections.somenamedtuple._asdict (which , despite the underscore, is public):

Amazing! This should work.

[Priyansh121096]

@MarcoGorelli I'll raise another PR for iter_rows soon. Can we merge this one?

[MarcoGorelli]

thanks - tbh I'm not really sure about DataFrame.rows, I might even suggest deprecating it altogether in Polars itself

could we just repurpose this one for DataFrame.iter_rows please? sorry for not having thought about this straight away

[Priyansh121096]

could we just repurpose this one for DataFrame.iter_rows please?

@MarcoGorelli pushed a change for this.

[MarcoGorelli]

@pre-commit.ci autofix