[SPARK-44887][DOCS] Fix wildcard import from pyspark.sql.functions import * in Quick Start Examples

[zhengruifeng]

What changes were proposed in this pull request?

Fix wildcard import from pyspark.sql.functions import * in https://spark.apache.org/docs/latest/quick-start.html

Why are the changes needed?

to follow the PEP 8 - Style Guide for Python Code

Wildcard imports (from import *) should be avoided, as they make it unclear which names are present in the namespace, confusing both readers and many automated tools. There is one defensible use case for a wildcard import, which is to republish an internal interface as part of a public API (for example, overwriting a pure Python implementation of an interface with the definitions from an optional accelerator module and exactly which definitions will be overwritten isn’t known in advance).
When republishing names this way, the guidelines below regarding public and internal interfaces still apply.

to avoid potential namespace conflicts, since there are several sql functions already shared the same names with built-in modules/functions (e.g. min/max/sum/hash)

Does this PR introduce any user-facing change?

yes

How was this patch tested?

CI

Was this patch authored or co-authored using generative AI tooling?

No

[zhengruifeng]

there are two wildcard import under ./docs:

(spark_dev_310) ➜  spark git:(master) ag -i 'import \*' docs
docs/sql-ref-datatypes.md
117:from pyspark.sql.types import *

docs/quick-start.md
133:>>> from pyspark.sql.functions import *
(spark_dev_310) ➜  spark git:(master) 

As to the from pyspark.sql.types import * in https://spark.apache.org/docs/latest/sql-ref-datatypes.html#data-types, I think we don't need to touch it, since there should not be any namespace conflicts as far as I know.

[zhengruifeng]

cc @HyukjinKwon @allisonwang-db @grundprinzip

[HyukjinKwon]

Merged to master.

[allisonwang-db]

Thanks for the fix! Shall we also merge it and all other docstring fixes and improvements to Spark 3.5?

[HyukjinKwon]

let's don't. improvements shouldn't go to other branches by right, and the 3.5 release is being soon.