Safe version of urljoin, joins the URIs carefully considering the prefixes and trailing slashes.

safe_urljoin.py

def safe_urljoin(*uris) -> str:
    """
    Joins the URIs carefully considering the prefixes and trailing slashes.
    The trailing slash for the end URI is handled separately.

    >>> safe_urljoin("https://px.com/", "adunits/", "/both/", "/left")
    >>> 'https://px.com/adunits/both/left'

    >>> safe_urljoin("https://px.com/", "adunits/", "/both/", "right/")
    >>> 'https://px.com/adunits/both/right/'

    >>> safe_urljoin("https://px.com/", "adunits/", "/both/", "right/", "none")
    >>> 'https://px.com/adunits/both/right/none'

    >>> safe_urljoin("https://px.com/", "adunits/", "/both/", "right/", "none/")
    >>> 'https://px.com/adunits/both/right/none/'
    """
    if len(uris) == 1:
        return uris[0]

    safe_urls = [
        f"{url.lstrip('/')}/" if not url.endswith("/") else url.lstrip("/")
        for url in uris[:-1]
    ]
    safe_urls.append(uris[-1].lstrip("/"))
    return "".join(safe_urls)