BUG: Groupby.transform(name) should only accept valid names

#27467 (comment)

Examples:

• g.transform('invalid_name')
• g.transform('agg'), attribute exists but isn't appropriate agg/transformation.

[Lucas-Marchand]

jreback, if this isn't already being worked on I would like to give it a shot at resolving this issue and contributing to the project

@Lucas-Marchand #27467 is supposed to close this.

[Lucas-Marchand]

good to know that these issues are actively being worked on! I will look around for other issues I can help contribute to.