How could one get the last element of the following list?
list1 = ["one", "two", "three", "four", "five", "six"]
The solution, coming from, say, C or Java would be similar to the following.
last1 = list1[len(list1)-1] print("last=[{0:s}]".format(last1))
And this does work, but is not Pythonic. Here is the Python code [#3]
list1 = ["one", "two", "three", "four", "five", "six"] last1 = list1[len(list1)-1] print("last=[{0:s}]".format(last1))
Here is the output of the Python code.
last=[six]

Python has a nice way to access parts of lists - individual and contiguous elements - using what is called a slice.

A negative index into a list is considered and index from the end of the list.
last1 = list1[-1] print("last=[{0:s}]".format(last1))
Here is the Python code [#5]
list1 = ["one", "two", "three", "four", "five", "six"] last1 = list1[-1] print("last=[{0:s}]".format(last1))
Here is the output of the Python code.
last=[six]
But the slice idea goes further - including parts of lists, list comprehensions, etc.

• See Python list comprehensions for more on list comprehensions.

The general form of a slice, by example, is as follows, where parts can be omitted as in the examples (that follow).

The general form of a slice, by example, is as follows (where expressions e1 and e2 evaluate to nonnegative integer values).

• list1 is the entire list.



• list1[e1] is the element at position e1 (from the start of the list).
• list1[-e1] is the element at position e1 from the end of the list.
• list1[e1:] is the list starting at position e1 to the end of the list
• list1[:e2] is the list from the beginning to the position (before) e2.
• list1[e1:e2] is the list from the position e1 to the position (before) e2.

Note that a string is considered a list of characters and the slice idea can be used with strings as well.

The index parameter allows one to iterate through the list in the selection process - as in a list comprehension.

• list1[::-1] returns the list with the order of the elements reversed.
• list1[::2] returns the list with every other element included.
• list1[::-2] returns the list with every other element included from the end of the list

Here is the Python code [#6]
list1 = ["one", "two", "three", "four", "five", "six"] text1 = str(list1) print("{0:s} (list)".format(text1)) list2 = list1[::-1] text2 = str(list2) print("{0:s} (list reversed)".format(text2)) list2 = list1[::2] text2 = str(list2) print("{0:s} (list every other element)".format(text2)) list2 = list1[::-2] text2 = str(list2) print("{0:s} (list every other element from end)".format(text2))
Here is the output of the Python code.
['one', 'two', 'three', 'four', 'five', 'six'] (list) ['six', 'five', 'four', 'three', 'two', 'one'] (list reversed) ['one', 'three', 'five'] (list every other element) ['six', 'four', 'two'] (list every other element from end)