I want to edit the .py file on Google Collaboration.

Wouldn't it be better to download the target file, edit it in the local environment, and then upload it on the side?

To be a little more specific, I'm going to use the package I installed on the Collaborative.

!pip show<package-name>

After confirming the installation location and checking the PATH of the target file,

 from google.colab import files
files.download (<PATH> for target files)

Download and edit to your local environment. After that,

files.upload()

Upload the edited file to the current directory and

!cp<Target Files><Target Files>PATH>Target Files

You can override it as .
If you want to use the edited file around, you may want to put it on Google Drive, mount it on the Collaboration, and copy it.

 from google.colab import drive
drive.mount('/content/drive')

!cp"/content/drive/My Drive/target file"<PATH> for target files

It's easier to use your own package, simply upload it to the current directory (or copy from Google Drive) and import it.