# Python Set issubset() Method – Tutorial with Examples

A set is an unordered collection of unique elements. Python provides several built-in methods for manipulating sets, including the `issubset()` method. The `issubset()` method returns a Boolean value indicating whether the set is a subset of another set.

## Syntax

```set.issubset(set)
```

The `issubset()` method takes one argument as a set and returns `True` if the set is a subset of the given set. Otherwise, it returns `False`.

## Return Value

• If the set is a subset of the given set, it returns `True`.
• If the set is not a subset of the given set, it returns `False`.

## Examples

### Example 1: Using issubset() method with two sets

Let’s create two sets and check if the first set is a subset of the second set using the `issubset()` method:

```# Create two sets
set1 = {1, 2, 3}
set2 = {1, 2, 3, 4, 5}

# Check if set1 is a subset of set2
result = set1.issubset(set2)

# Print the result
print(result)
```

Output:

`True`

In the above example, we created two sets (`set1` and `set2`) and checked if `set1` is a subset of `set2` using the `issubset()` method. Since all the elements of `set1` are present in `set2`, the method returns `True`.

### Example 2: Using issubset() method with a superset

Let’s create a set and check if it is a subset of a superset using the `issubset()` method:

```# Create a set and a superset
set1 = {1, 2, 3}
superset = {1, 2, 3, 4, 5}

# Check if set1 is a subset of superset
result = set1.issubset(superset)

# Print the result
print(result)
```

Output:

`True`

In the above example, we created a set (`set1`) and a superset (`superset`) and checked if `set1` is a subset of the superset using the `issubset()` method. Since all the elements of `set1` are present in `superset`, the method returns `True`.

### Example 3: Using issubset() method with a non-subset

Let’s create two sets and check if the first set is a subset of the second set using the `issubset()` method:

```# Create two sets
set1 = {1, 2, 3, 4}
set2 = {1, 2, 3}

# Check if set1 is a subset of set2
result = set1.issubset(set2)

# Print the result
print(result)
```

Output:

`False`

In the above example, we created two sets (`set1` and `set2`) and checked if `set1` is a subset of `set2` using the `issubset()` method. Since `set1` contains an element (4) that is not present in `set2`, the method returns `False`.

## Use Cases

The `issubset()` method is particularly useful when dealing with large sets, as it allows you to quickly check whether one set is a subset of another set. This can be useful in a variety of applications, such as:

• Checking if a specific set of items is present in a larger dataset
• Determining if a user has access to a particular set of resources or permissions
• Comparing two different sets of data to see if they share any common elements

Overall, the `issubset()` method is a powerful tool for working with sets in Python, and can be used in a wide range of applications.