Google Storage Downloader

I need software that downloads from a list of csv files.
My csv file contains thousands of lines containing the directory and file name, ex: dir1/dir2/dir3/file.xyz
Screen layout:
Text and window Title "Mapzer Google Storage Mass Downloader"
Fields:
Project: up to 50 characters, save for next opening
BucketName: up to 50 characters, save for next opening
KeyId: up to 50 characters, save for next opening
SecretKey: up to 50 characters, do not save
File: file picker, filtered by .csv extension, do not save
Text containing number of valid lines of .csv files
Directory: directory selector, save
Button "Download"
Progress Bar with count success file downloaded

the software must be developed in python or c# for desktop, not web