def upload_files(drive: GoogleDrive, source: str, target: str='') -> None:
"""Uploads file(s) to google drive
Uploads all files to the target folder, even if they are contained
in distinct folders originally.
Args:
drive: The google drive in question
source: glob-expression of file(s) to be uploaded.
target: Target folder in the google drive (if non-existent will be created)
"""
file_list = glob.glob(source)
target_folder = drive.make_dir(target)
for f in file_list:
name = os.path.split(f)[-1]
metadata = {
'title': name,
'parents': [{'id': target_folder['id']}]
}
file = drive.CreateFile(metadata)
file.Upload()
file.SetContentFile(f)
file.Upload()
