Another type of collection that Python provides support for is tuples.<\/p>\n
Tuples<\/strong><\/p>\n Tuples are used to store comma separated values enclosed in parentheses, example:<\/p>\n \nNote: If the tuple has only one element, a comma after the element is needed, example:<\/p>\n \nTuples retain their order and, unlike lists, elements in a tuple may not be changed. \nTuples may also be indexed with negative values starting at the last element. Reverse indexing starts at – 1 and decreases by -1. For example, this would also print the third element value in the tuple, which is ‘wash car’:<\/p>\n \nTuples may be looped through by using the in keyword:<\/p>\n \n print(item)<\/p>\n \nPython provides support for a couple of built in tuple functions. These functions are as follows:<\/p>\n count<\/strong> – Returns the number of elements in the tuple with the given input value. Example: <\/p>\n \nindex<\/strong> – Returns the index of the input value. Example: <\/p>\n A couple of other useful Python methods for tuples are:<\/p>\n len<\/strong> – Returns the number of elements in a tuple. Example: <\/p>\n \nmin<\/strong> – Returns the item with the minimum value. Example: <\/p>\n \nmax<\/strong> – Returns the item with the maximum value. Example: <\/p>\n \ntuple<\/strong> – Constructor used to create a tuple. Example: <\/p>\n Slicing<\/strong><\/p>\n Slicing, which is accessing ranges of collection items, works exactly the same way for tuples as it does for lists. Extract elements 2 – 3 which would be indexes 1 – 2.<\/p>\n Using the original tuple, this returns: to_do_tuple[‘laundry’, ‘wash car’] which is: If the beginning index is not included, the slicing starts at the first element in the tuple.<\/p>\n If the ending index is not included, the slicing ends at the last element in the tuple.<\/p>\n If neither the beginning index or ending index is included, the slicing starts at the first element and ends at the last element.<\/p>\nto_do_tuple = ('groceries', 'laundry', 'wash car', 'vacuum')<\/pre>\nto_do_tuple = ('groceries',)<\/pre>\n
\nTuple elements have a corresponding index value. Indexing starts at 0 and increases by 1. Elements are accessed by using their index value.
\nFor example this would print the third element value in the tuple, which is ‘wash car’:<\/p>\nprint(to_do_tuple[2])<\/pre>\n
print(to_do_tuple[-2])<\/pre>\n
for item in to_do_tuple:<\/pre>\n
to_do_tuple.count('vacuum')<\/pre>\nto_do_tuple.index('vacuum')<\/pre>\nnum = len(to_do_tuple)<\/pre>\n
to_do_tuple.min() # returns 'groceries<\/pre>\n
to_do_tuple.max() # returns 'wash car<\/pre>\n
new_tuple = tuple(('exercise', 'shovel snow'))<\/pre>\n
\nAs review, slicing is done by indexing the tuple with a beginning index followed by a colon and an ending index. The beginning index is inclusive. The ending index is exclusive. Example:<\/p>\nextracted_tuple = to_do_tuple[1:3]<\/pre>\n
\n[element 2, element 3] which is:
\n[index 1, index 2]<\/p>\nextracted_tuple = to_do_tuple[:3] # returns to_do_tuple['groceries', 'laundry', 'wash car']<\/pre>\n
extracted_tuple = to_do_tuple[1:] # returns to_do_tuple['laundry', 'wash car', 'vacuum']<\/pre>\n
extracted_tuple = to_do_tuple[:] # returns to_do_tuple['groceries', 'laundry', 'wash car', 'vacuum']<\/pre>\n