Polars: py-0.17.9 Release

Migration guide.

Operation that require columns to be sorted will now give a warning if they are not explicitly sorted, or tagged as sorted.

# 1. inform polars that a column is sorted on the DataFrame / LazyFrame.
(
    df.set_sorted("foo")
    .groupby_dynamic(..)
)

# 2. inform polars inline via the `set_sorted` expression
df.join_asof(df2, on=pl.col("foo").set_sorted())

# 3. explicitly sort first 
# this is expensive if the data is already sorted
df.sort("foo")

✨ Enhancements

• expose quantile/mean for duration (#8491)
• require explicitly sorted flag for upsample (#8488)
• allow for _saturating suffix in duration strings (#8479)

🐞 Bug fixes

• don't error on cast if column is not projected (#8495)
• ensure window function succeeds on empty frame (#8492)
• don't set verbose on union (#8487)
• check literal/group length before claiming agg sta… (#8486)

🛠️ Other improvements

• Remove unneeded operation in strptime (#8496)
• additional parametric testing docs/examples (#8485)
• improve sorted warning/ fix tests (#8484)

Thank you to all our contributors for making this release possible! @MarcoGorelli, @alexander-beedie, @ritchie46 and @stinodego