I don't think it is. First, a correction, Python predates Nix by 12 years, not decades, the first experimentation with what would later be named Nix was published in 2003 by Eelco Dolstra[1]; the 2004 paper[2] refers to it specifically as Nix. However, we aren't comparing Nix (language) to Python, we're comparing Nix (package manager) to easy_install and more recently pip, released in 2004 and 2011 respectively. It's 2019 now, and I don't think it's longer unreasonable to expect what Nix is capable of, of your package manager.
