def parse_reqs(req_path="./requirements.txt"):
    """Recursively parse requirements from nested pip files."""
    install_requires = []
    with open(req_path, "r") as handle:
        # remove comments and empty lines
        lines = (line.strip() for line in handle if line.strip() and not line.startswith("#"))
        for line in lines:
            # check for nested requirements files
            if line.startswith("-r"):
                # recursively call this function
                install_requires += parse_reqs(req_path=line[3:])
            else:
                # add the line as a new requirement
                install_requires.append(line)
    return install_requires