List Comprehension

Sum

sum([value for value in list_of_values])

If

[item for item in item_list if item == 'something']

Map

def foo(bar):
    return [x for x in map(dictionary.get, list[bar])]
    # [dictionary[i] for i in object]

Reorder

[list(string.ascii_lowercase)[i % 26] for i in range(start_at_index, 26 + start_at_index)]

Alternate to reordered
source: https://docs.python.org/2/library/collections.html

from collections import deque

my_sequence = 'abcdefg'
my_sequence.rotate(-3)

List of strings to list of characters

char_list = list(''.join(['abc', 'def', 'ghi]))

Flatten list of lists

print([item for sublist in [['a', 'b', 'c'], ['d', 'e', 'f'], ['g', 'h', 'i']] for item in sublist])