Python Tutorial

PYTHON DATA STRUCTURE

Data Structure is a way to organizing and storing data in computer memory so that we can access and modify it efficiently. In this post, we will learn about some cool feature of python data structure.

Python Data Structure

Python has following commonly used data structure.

• List
• Tuple
• Set
• Dictionary

In our previous post, we have already learned a lot about the list. In this post, we will learn about Tuple, Set, and Dictionary data structure.

Tuple

A tuple consists of a number of values separated by commas.

Create Tuple

#Question: Create a tuple of numbers 1, 2, 3, 4, 5
#Answer:
my_tuple = 1, 2, 3, 4, 5
or, my_tupe = (1, 2, 3, 4, 5)

Both of above syntax is correct.
There is the special syntax to construct of tuples containing 0 or 1 items.

#Question: Create tuple contain 0 item
#Answer: my_tuple = ()
#Question: Create tuple contain 1 item
#Answer: my_tuple = '1',

Empty tuples are constructed by an empty pair of parentheses; a tuple with one item is constructed by following a value with a comma.

Access Tuple

#Question: Access 3 from my_tuple = (1, 2, 3, 4, 5)
#Answer: my_tuple[2] = 3

Above syntax is perfectly fine but generally, we access tuple item by unpacking.

my_tuple = (1, 2, 3, 4, 5) #packing
a, b, c, d, e = my_tuple #unpacking

Update Tuple

my_tuple = (1, 2, 3, 4, 5) 
my_tuple[1] = 5

Above statement is not correct. we generally can not update a tuple because it is not mutable.

Nested Tuple

Tuple is immutable but it may contain a mutable data structure and we can modify/update it.

my_tupple = ([1, 2, 3, 4, 5], [1, 3, 10])
my_tuple[0][1] = 5
print (my_tuple)
#([1, 5, 3, 4, 5], [1, 3, 10])

Traverse Tuple

my_tuple = (1, 2, 3, 4, 5)
for x in my_tuple:
     print (x)

Set

A set is an unordered data structure with no duplicate. Set also support basic mathematical operations like union, intersection, difference, and symmetric difference. Curly braces or set() function used to create set to create empty set we have to use set() not {}.

my_set = {1, 2, 3, 4, 5} #create set
my_set1 = set(1, 2, 3, 4, 5) #create set
my_set - my_set1 #return numbers in my_set but not in my_set1
my_set | my_set1 #return union
my_set & my_set1 #return intersection
my_set ^ my_set1 #return union - intersection

Traverse Set

my_set = {1, 2, 3, 4, 5}
for x in my_set:
     print (x)

Set does not support indexing so we can not write my_set[0]  to access a set item.

Dictionary

Dictionary is an unordered set of key : values pair, with the requirement that the keys are unique.

Create Dictionary

my_dictionary = {1: 'A', 2: 'B', 3: 'C', 4: 'D', 5: 'E'} #create dictionary
my_dictionary = {} #create empty dictionary

Access Dictionary

We can access dictionary values using the key.

my_dictionary[1] #return 'A' 

Update Dictionary

my_dictionary = {1: 'A', 2: 'B', 3: 'C', 4: 'D', 5: 'E'} #create dictionary
my_dictionary[1] = 'E' # my_dictionary = {1: 'E', 2: 'B', 3: 'C', 4: 'D', 5: 'E'}

Traverse Dictionary

my_dictionary = {1: 'A', 2: 'B', 3: 'C', 4: 'D', 5: 'E'}
for k, v in my_dictionary.items():
     print (k, v)

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.