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https://issues.apache.org/jira/browse/SPARK-38483?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17504448#comment-17504448
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Brian Schaefer commented on SPARK-38483:
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Could you provide an example of when the real column names would be different?
At least for basic examples, it looks like the real column names match those
found using {{{}Column._jc.toString(){}}}. With some careful regex it may also
be possible to catch aliases.
{code:python}
>>> df = spark.createDataFrame([{"values": [1,2,3]}])
>>> values = F.col("values")
>>> print(df.select(values).schema[0].name)
values
>>> print(values._jc.toString())
values
>>> import re
>>> aliased_values = F.col("values").alias("aliased")
>>> print(df.select(aliased_values).schema[0].name)
aliased
>>> print(re.match(".*`(.*)`", aliased_values._jc.toString())[1])
aliased
{code}
> Column name or alias as an attribute of the PySpark Column class
> ----------------------------------------------------------------
>
> Key: SPARK-38483
> URL: https://issues.apache.org/jira/browse/SPARK-38483
> Project: Spark
> Issue Type: New Feature
> Components: PySpark
> Affects Versions: 3.2.1
> Reporter: Brian Schaefer
> Priority: Minor
> Labels: starter
>
> Having the name of a column as an attribute of PySpark {{Column}} class
> instances can enable some convenient patterns, for example:
> Applying a function to a column and aliasing with the original name:
> {code:java}
> values = F.col("values")
> # repeating the column name as an alias
> distinct_values = F.array_distinct(values).alias("values")
> # re-using the existing column name
> distinct_values = F.array_distinct(values).alias(values._name){code}
> Checking the column name inside a custom function and applying conditional
> logic on the name:
> {code:java}
> def custom_function(col: Column) -> Column:
> if col._name == "my_column":
> return col.astype("int")
> return col.astype("string"){code}
> The proposal in this issue is to add a property {{Column.\_name}} that
> obtains the name or alias of a column in a similar way as currently done in
> the {{Column.\_\_repr\_\_}} method:
> [https://github.com/apache/spark/blob/master/python/pyspark/sql/column.py#L1062.]
> The choice of {{_name}} intentionally avoids collision with the existing
> {{Column.name}} method, which is an alias for {{{}Column.alias{}}}.
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