7.6: List Methods
- Page ID
- 21215
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Python provides methods that operate on lists. For example, append adds a new element to the end of a list:
>>> t = ['a', 'b', 'c']
>>> t.append('d')
>>> print(t)
['a', 'b', 'c', 'd']extend takes a list as an argument and appends all of the elements:
>>> t1 = ['a', 'b', 'c']
>>> t2 = ['d', 'e']
>>> t1.extend(t2)
>>> print(t1)
['a', 'b', 'c', 'd', 'e']This example leaves t2 unmodified.
sort arranges the elements of the list from low to high:
>>> t = ['d', 'c', 'e', 'b', 'a']
>>> t.sort()
>>> print(t)
['a', 'b', 'c', 'd', 'e']Most list methods are void; they modify the list and return None. If you accidentally write t = t.sort(), you will be disappointed with the result.