About
Slicing (sub-list) returns a list of elements in a sequence from the position a to the position before b.
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Syntax
sequence[a:b:c]
where in the sequence[a:b:c]:
- a is the first element of the slice. It can be negative (ie -2 means start from the last two elements of list)
- b is the last element of the slice (not include)
- c is the number of element to skip
Example
without skipping
my_list = [0, 1, 2, 3]
first_three_items = my_list[0:3] # The first three items
first_three_items = my_list[:3] # of
last_two_items = my_list[len(my_list)-2:] # will return the last two items
print my_list
# Prints [0, 1, 2, 3]
print first_three_items
# Prints [0, 1, 2]
print last_two_items
# Prints [2,3]
With skipping
>>> my_list = [0, 1, 2, 3]
>>> my_list[::2]
[0, 2]
>>> my_list[1::2]
[1, 3]