Looking for element in tuple inside list via len() as a boolean. Too cool to forget.

list_tup_lokky.py

t = [
    ('a', 'b'),
    ('c', 'd')
]
if len([item[1] for item in t if item[0] == 'a']):
    print 'yes'
else:
    print 'no'
# yes
if len([item[1] for item in t if item[0] == 'e']):
    print 'yes'
else:
    print 'no'
# no