x = x = [i*2 for i in [j+1 for j in range(20) if (j%3) == 0] if i*i > 19]


print x
[14, 20, 26, 32, 38]

y = [j+1 for j in range(20) if (j%3) == 0]
print y
[1, 4, 7, 10, 13, 16, 19]

fruit = ["kiwi", "lemon", "peach", "somereallylongfruit", "grape"]
x = [f for f in fruit if len(f)==max([len(f) for f in fruit])][0]
print x
grape

# Don't use the same variable for both list comprehensions!
# This answer is wrong and weird!
y = [f for f in fruit if len(f)==max([len(v) for v in fruit])][0]
print y
somereallylongfruit

# this time I used two variables, f and v
 


z = [len(v) for v in fruit]
print z
[4, 5, 5, 19, 5]


fruit = ["apple", "peach", "kiwi", "lemon", "lime"]
y = [f for f in fruit if len(f)==max([len(v) for v in fruit])][0]
print y
apple


colorlist = ['red', 'blue', 'red', 'red, 'green']
  File "<ipython-input-16-cf49e1bc3b0b>", line 1
    


colorlist = ['red', 'blue', 'red', 'red, 'green']
                                                  ^
SyntaxError: invalid syntax

colorlist = ['red', 'blue', 'red', 'red', 'green']
print colorlist
['red', 'blue', 'red', 'red', 'green']


colorset = set(colorlist)
print colorset
set(['blue', 'green', 'red'])

colorset.add("red")
print colorset
set(['blue', 'green', 'red'])

colorset.add("yellow")
print colorset
set(['blue', 'green', 'yellow', 'red'])

x = list(colorset)
print x
['blue', 'green', 'yellow', 'red']

colorset.remove('yellow')
print colorset
set(['blue', 'green', 'red'])

colorset.remove("purple")
Traceback (most recent call last):
  File "C:\Users\Susan\AppData\Local\Enthought\Canopy\User\lib\site-packages\IPython\core\interactiveshell.py", line 2885, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-29-861da2f6599e>", line 1, in <module>
    colorset.remove("purple")
KeyError: 'purple'