set&dict

Sets and dictionaries are unordered collections of items.

They serve different purposes due to their unique properties.

In Common Unordered

• Both sets and dictionaries do not have a defined order for their elements. This means you cannot rely on the order of insertion or any other order when iterating over them. The elements are stored in a way that makes retrieval efficient, but the order of elements is not guaranteed.

In Common Mutability

• meaning you can add or remove elements from a set.
• Dictionaries are mutable as well, allowing for the addition, removal, or modification of key-value pairs.

# Adding elements to a set
my_set.add(6)
print(my_set)  # Output: {1, 2, 3, 4, 5, 6}

# Adding a new key-value pair to a dictionary
my_dict['d'] = 4
print(my_dict)  # Output: {'a': 1, 'b': 2, 'c': 3, 'd': 4}

differences between sets and dictionaries:

Accessing Elements:

• Sets are accessed by iterating over the set or by checking for membership.
• Dictionaries are accessed using keys.

# Accessing elements in a set
for element in my_set:
    print(element)  # Output: 1, 2, 3, 4, 5

# Accessing elements in a dictionary
print(my_dict['a'])  # Output: 1

About accessing dictionaries

Sets:

• A set is a collection of unique elements. Each element in a set must be unique, and duplicate elements are automatically removed.
• Sets are unordered, meaning the elements are not stored in any particular order.
• Sets are typically used when you want to perform operations like intersection, union, and difference between collections.

Example

# Creating a set
my_set = {1, 2, 3, 4, 5}
print(my_set)  # Output: {1, 2, 3, 4, 5}

Dictionaries:

• A dictionary is a collection of key-value pairs. Each element in a dictionary consists of a key and its associated value.
• Dictionaries are unordered as well, but from Python 3.7 onwards, insertion order of keys is preserved. In Python 3.6 and earlier, dictionaries are unordered.
• Keys in a dictionary must be unique, but the values can be duplicated.
• Dictionaries are useful for storing and retrieving data based on some unique identifier (the key).

Example

# Creating a dictionary
my_dict = {'a': 1, 'b': 2, 'c': 3}
print(my_dict)  # Output: {'a': 1, 'b': 2, 'c': 3}

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Data Type	Content Type	Sequence	Mutable	defined Order
string	characters	yes	no
list	anything	yes	yes
tuple	anything	yes	no
range	integers	yes	no
set	immutable items	no	yes	unordered collections
dictionary	immutable items	no	yes	unordered collections