I think you should change this line:
if locations == ['London']: // status.user.location returns a string, not a list!
to:
if locations == 'London':
Your code didn't work because status.user.location
returned a string and you compared this string with a list. That couldn't work.
And one other thing: since status.user.location
can be "London, England" it's better to do some normalization and check on substring inclusion:
if 'london' in locations.lower():