import re
linha = "joao foi no mercado http://s...content-available-to-author-only...n.org/stable/modules/genera quero que esse texto apareça"
URLless_string = re.sub(r'\w+:\/{2}[\d\w-]+(\.[\d\w-]+)*(?:(?:\/[^\s/]*))*','', linha)
print(URLless_string)
aW1wb3J0IHJlCgpsaW5oYSA9ICJqb2FvIGZvaSBubyBtZXJjYWRvIGh0dHA6Ly9zLi4uY29udGVudC1hdmFpbGFibGUtdG8tYXV0aG9yLW9ubHkuLi5uLm9yZy9zdGFibGUvbW9kdWxlcy9nZW5lcmEgcXVlcm8gcXVlIGVzc2UgdGV4dG8gYXBhcmXDp2EiCgpVUkxsZXNzX3N0cmluZyA9IHJlLnN1YihyJ1x3KzpcL3syfVtcZFx3LV0rKFwuW1xkXHctXSspKig/Oig/OlwvW15ccy9dKikpKicsJycsIGxpbmhhKQoKcHJpbnQoVVJMbGVzc19zdHJpbmcp