def do_remove_first(s, remove):
    """
    Removes only the first occurrence of the specified substring from a string.
    https://github.com/Shopify/liquid/blob/b2feeacbce8e4a718bde9bc9fa9d00e44ab32351/lib/liquid/standardfilters.rb#L218
    """
    return s.replace(str(remove), '', 1)