The **python set difference() method** is used to show the difference between two set elements as you learn in mathematics. First now understand,

## How the Python difference() method works

Suppose we have the following two sets :

A = {1,2,3,4,5,6}

B = {1,2,3,8,7}

The difference between A and B is,

A-B = {4,5,6}

Firstly remove the common elements. Now, the element left in the first set is your answer. As we can see in the above example, In set A and B {1,2,3} are common so remove that. Now, the first set (A) is left with {4,5,6} element i.e our answer.

The difference between B and A is,

B-A = {8,7}

As we can see, in the python set A and B {1,2,3} elements are common so remove that. Now, the first set (B) is left with {8,7} element i.e our answer.

*Note: A-B is equal to the elements present in A but not in B. B-A is equal to the elements present in B but not in A.*

## Python difference() method Syntax :

`Firstset.difference(second set) `

**As per the above syntax, we can write as below.**

**A.difference(B) ***that means A-B***B.difference(A)** *that means B-A*

Now, let’s understand with the help of examples.

### Example 1:

`A={12,3,4,6}`

B={12,9,10,11}

print("A-B is",A.difference(B))

print("B-A is",B.difference(A))

### Output :

```
A-B is {3, 4, 6}
B-A is {9, 10, 11}
```

### Example 2:

```
A={12,3,4,6}
B={12,9,10,11}
print(A-B)
```

### Output :

`{3, 4, 6}`

If all elements of the first set are present in the second set then it will return the null set (empty set).

### Example 3:

`A={12,4,6}`

B={12,4,6,9,10,11}

print("A-B is" ,A-B)

print("B-A is", B-A)

### Output :

```
A-B is set()
B-A is {9, 10, 11}
```