Pushing local repository to remote repository using python Github
Octal permission fields
77

is likely incorrect. What you've written is 77 in decimal, but this would work out to 115 in octal. If you wanted 077 in octal, you would actually need to write 0o077.
Pathlib
Consider replacing os.path with use of pathlib.
Argument parsing
The argv parsing that you've done is fragile - it will fail with an invalid-index exception if the user provides insufficient parameters. Consider using argparse instead.
Also: do not ask for a password as part of a command line, since it will be stored in the user's shell history. Accept it from an environmental variable, a secure wallet, or from stdin via getpass (not input).
String interpolation
&quot;https://github.com/&quot;+username+&quot;/&quot;+output_repo_name+&quot;.git&quot;

is more easily written as
f'https://github.com/{username}/{output_repo_name}.git'