os.system to invoke an exe which lies in a dir whose name contains whitespace

Putting quotes around the path will work:

file = 'C:\\Exe\\First Version\\filename.exe'
os.system('"' + file + '"')

but a better solution is to use the subprocess module instead:

import subprocess
file = 'C:\\Exe\\First Version\\filename.exe'
subprocess.call([file])

I used this:

import subprocess, shlex
mycmd='"C:\\Program Files\\7-Zip\\7z" x "D:\\my archive.7z" -o"D:\\extract folder" -aou'
subprocess.run(shlex.split(mycmd))

Try enclosing it with double quotes.

file = '"C:\\Exe\\First Version\\filename.exe"'
os.system(file)