--description--

Augmented assignment combines a binary operation with an assignment in one step. It takes a variable, applies an operation to it with another value, and stores the result back into the same variable.

If you're familiar with a language like JavaScript, you've probably heard of the addition assignment operator (+=) or subtraction assignment (-=), and others. Those exist in Python, too. The only difference is that they're referred to as augmented assignments.

The basic syntax of an augmented assignment looks like this:

variable <operator>= value

Which is a more efficient way of doing this:

variable = variable <operator> value

For example, here's an example of using augmented assignment to add 5 to an existing variable:

my_var = 10
my_var += 5

print(my_var) # 15

And here is the same thing, but without augmented assignment:

my_var = 10
my_var = my_var + 5

print(my_var) # 15

The advantage of augmented assignment is that it provides a concise and readable way to update a variable value without repeating the variable name. In turn, this reduces redundancy and potential errors that might arise from a typo or something similar.

Every operator can use an augmented assignment. We've looked at the addition assignment operator (+=), so let's look at others.

• The subtraction assignment operator (-=) subtracts the right operand from the left variable and stores the difference in the left variable:

count = 14
count -= 3

print(count) # 11

• The multiplication assignment operator (*=) multiplies the left variable by the right operand and stores the product back in the left variable:

product = 65
product *= 7

print(product) # 455

• The division assignment operator (/=) divides the left variable by the right and stores the result back in the left variable:

price = 100
price /= 4

print(price) # 25.0

• The floor division operator (//=) floor‑divides the left variable by the right and stores the result back in the left variable:

total_pages = 23
total_pages //= 5

print(total_pages) # 4

• The modulo assignment operator (%=) computes the remainder of the left variable divided by the right and stores it back in the left variable:

bits = 35
bits %= 2

print(bits) # 1

• The exponentiation assignment operator (**=) raises the left variable to the power of the right and stores the result back in the left variable:

power = 2
power **= 3

print(power) # 8

You can use some augmented assignment operators with strings, too. For example, the addition assignment operator makes it easy to concatenate strings:

greet = 'Hello'
greet += ' World'

print(greet) # Hello World

And the multiplication assignment operator can be used to repeat a string:

greet = 'Hello'
greet *= 3

print(greet) # HelloHelloHello

Other augmented assignments throw a TypeError when you use them with strings:

greet = 'Hello'
greet -= ' World'

print(greet) # TypeError: unsupported operand type(s) for -=: 'str' and 'str'


greet = 'Hello'
greet /= 'World'

print(greet) # TypeError: unsupported operand type(s) for /=: 'str' and 'str' 

If you're wondering if increment and decrement operators (++ and  --) work in Python, they don't. That's because Python deliberately avoids C-style increment and decrement shortcuts in order to keep the language clear and explicit.

Instead of x++, you can simply write x += 1, which makes it obvious that you're incrementing the value of x by 1.

Writing ++x in Python just applies the unary plus twice, and does not increment anything:

my_var = 5

print(+my_var)   # 5
print(++my_var)  # 5
print(+++my_var) # 5

my_var += 1

print(my_var) # 6

--questions--

--text--

What is the main advantage of using augmented assignment operators?

--answers--

They automatically convert data types.

--feedback--

Think about how augmented assignments help avoid redundancy and reduce typing mistakes.

They prevent all possible syntax errors.

--feedback--

Think about how augmented assignments help avoid redundancy and reduce typing mistakes.

They provide a concise way to update variables without repeating the variable name.

They make mathematical operations faster.

--feedback--

Think about how augmented assignments help avoid redundancy and reduce typing mistakes.

--video-solution--

3

--text--

What happens when you use the increment (++) and decrement (--) operators in Python?

--answers--

They work exactly like in C/C++.

--feedback--

Think about how Python avoids C-style increment and decrement operators.

They cause a syntax error and crash the program.

--feedback--

Think about how Python avoids C-style increment and decrement operators.

They are interpreted as double unary operators with no actual increment/decrement.

They only work in Python 2 but were removed in Python 3.

--feedback--

Think about how Python avoids C-style increment and decrement operators.

--video-solution--

3

--text--

Which augmented assignment operator raises a variable to a power and stores the result back to that variable?

--answers--

^=

--feedback--

Think about the operator that uses the same symbol as exponentiation operator.

**=

*=

--feedback--

Think about the operator that uses the same symbol as exponentiation operator.

^^=

--feedback--

Think about the operator that uses the same symbol as exponentiation operator.

--video-solution--

2