import re
rx = r"blackpages\.com/([^/]*)"
ss = ["http://w...content-available-to-author-only...s.com/cityName-StateName/mip/part-I-want-to-extract/randomCharacters",
"http://w...content-available-to-author-only...s.com/cityName-StateName/part-I-want-to-extract/randomCharacters"]
for s in ss:
m = re.search(rx, s)
if m:
print(m.group(1))
aW1wb3J0IHJlCnJ4ID0gciJibGFja3BhZ2VzXC5jb20vKFteL10qKSIKc3MgPSBbImh0dHA6Ly93Li4uY29udGVudC1hdmFpbGFibGUtdG8tYXV0aG9yLW9ubHkuLi5zLmNvbS9jaXR5TmFtZS1TdGF0ZU5hbWUvbWlwL3BhcnQtSS13YW50LXRvLWV4dHJhY3QvcmFuZG9tQ2hhcmFjdGVycyIsCiJodHRwOi8vdy4uLmNvbnRlbnQtYXZhaWxhYmxlLXRvLWF1dGhvci1vbmx5Li4ucy5jb20vY2l0eU5hbWUtU3RhdGVOYW1lL3BhcnQtSS13YW50LXRvLWV4dHJhY3QvcmFuZG9tQ2hhcmFjdGVycyJdCmZvciBzIGluIHNzOgoJbSA9IHJlLnNlYXJjaChyeCwgcykKCWlmIG06CgkJcHJpbnQobS5ncm91cCgxKSkK