Tuples and Lists

Creating tuples

A tuple is a sequence of elements that cannot be modified. They are useful to group elements of different type.

t = ('bananas','200g',0.55)

Creating lists

A list is a sequence of elements that can be modified. In many cases, all elements of a list will have the same type.

l = ['apples',
'bananas',
'oranges']

Accessing elements of lists and tuples

Using square brackets, any element of a list and tuple can be accessed. The first character has the index 0.

l = [1,2,3,4]
print l[0] # first
print l[3] # last
print l[-1] # last
l[0] = 'kiwi' # assigning an element

Creating lists from other lists

Lists can be sliced by applying square bracketsin the same way as substrings.

l = [0,1,2,3,4,5]
print l[1:3] # [1,2]
print l[0:2] # [0,1]
print l[:3] # [0,1,2]
print l[-2:] # [4,5]
m = l[:] # creates a copy!

List functions

l[0] = 'kiwi' # assigning an element

Adding elements to a list:

l.append(5) # adds at the end

Removing elements from a list:

l.remove(3)

l.pop() # removes last element

Sorting a list

l.sort()

Count elements:

l.count(3)