can we install python in sagemaker instance using subprocess.run?

Subprocess is part of the Python standard library. This means to use it, you will need Python installed already.

Python is installed on Sagemaker notebook instances, except for the kernels (Spark, SparkR, R). So, if you chose a kernel with python installed already, you don't have to worry about installing it.

Available kernels: https://docs.aws.amazon.com/sagemaker/latest/dg/nbi-al2.html#nbi-al2-kernel