In this session, we’ll look at Python’s += operator. Let us see how it works with a few simple examples.

The addition assignment operator is denoted by the operator ‘+=’. It is like a short form to it. It adds two values and stores the result in a variable (left operand).

#### Addition of Two numbers Using += Operator:

**Example1:**

gvn_num = 100 print("The given number = ", gvn_num) gvn_num += 50 print("The given number after addition with 50 = ", gvn_num)

**Output:**

The given number = 100 The given number after addition with 50 = 150

**Example2:**

a = 10 b = 20 c = 30 rslt_sum = 0 # Adding a,b,c and storing it in a variable rslt_sum # The below indicates rslt_sum = rslt_sum+(a+b+c) rslt_sum += a+b+c print("The sum of a,b,c = ", rslt_sum)

**Output:**

The sum of a,b,c = 60

#### For Strings

The ‘+=’ operator concatenates the given strings. It is used for the concatenation of two or more strings.

**Example1:**

gvn_fststr = "hello" gvn_scndstr = "btechgeeks" print("The given first string = ", gvn_fststr) print("The given second string = ", gvn_scndstr) print() # It concatenates the given first string with the second string and assigns the # result to the first string gvn_fststr += gvn_scndstr print("The given first string after concatenation = ", gvn_fststr)

**Output:**

The given first string = hello The given second string = btechgeeks The given first string after concatenation = hellobtechgeeks

**Example2:**

gvn_fststr = "hello" gvn_scndstr = " this is " gvn_thrdstr = "btechgeeks" concat_str = "" # concatenating the given three strings using '+=' Operator concat_str += (gvn_fststr+gvn_scndstr+gvn_thrdstr) print("The concatenation of given three strings = ", concat_str)

**Output:**

The concatenation of given three strings = hello this is btechgeeks

#### The “+=” operator’s Associativity in Python

The ‘+=’ operator’s associativity property is from right to left.

**Example1:**

a = 3 b = 6 a += b >> 2 print("a =", a) print("b =", b)

**Output:**

a = 4 b = 6

**Explanation:**

We set the starting values of two variables, **a** and **b**, to 3 and 6, respectively. In the code, we right shift the value of **b** by two bits, add the result to variable **‘a’**, and put the final result in variable** ‘a’**.

Therefore the final output is :

a=4 and b=6

**Example2:**

a = 3 b = 6 # Left shift by 1 bit a += b << 1 print("a =", a) print("b =", b)

**Output:**

a = 15 b = 6

**Conclusion**

This is about the Python ‘+=’ operator and its numerous implementations.