ArcPy - Move feature class into feature dataset?

[MarcusSanders2]

How do I move a feature class into a feature dataset using ArcPy?

I've tried both arcpy.CopyFeatures_management() and arcpy.Copy_management, which both give me these errors:

ExecuteError: ERROR 000725: Output Feature Class: Dataset G:\GIS Data\xxxxxx\..._20180209 already exists.  ‍‍‍

In this case, an empty feature dataset is created to store these feature classes. I just want to be able to move them into the datasets.

I also just tried arcpy.FeatureClassToFeatureClass_conversion() with no success:

ExecuteError: ERROR 999999: Error executing function. Failed to execute (FeatureClassToFeatureClass). ‍

[Lake_Worth_BeachAdmin · Accepted solution]

use the feature class to geodatabase function

Feature Class To Geodatabase—Conversion toolbox | ArcGIS Desktop 

[MarcusSanders2]

Thank you, that was it