What Do +=, -= Mean?
Operators like +=, -=, which combine an operator with an = sign, are called Compound Assignment Operators.
For instance, x += y means the same as x = x + y, where the value of x is updated by adding y to x.
Example of Compound Assignment Operators
x = 10
y = 5
x += y # x = x + y
print(x) # 15
Types of Compound Assignment Operators
In Python, compound assignment operators include += (addition), -= (subtraction), *= (multiplication), /= (division), %= (modulus), and others.
Example of Compound Assignment Operators
number = 10
print("number:", number) # 10
number += 5 # number = number + 5
print("number += 5:", number) # 15
number -= 3 # number = number - 3
print("number -= 3:", number) # 12
number *= 2 # number = number * 2
print("number *= 2:", number) # 24
number /= 4 # number = number / 4
print("number /= 4:", number) # 6.0
number %= 2 # number = number % 2
print("number %= 2:", number) # 0.0
Compound assignment operators are often used in loops, such as when adding numbers from 1 to 5.
Note: For more details about loops, refer to the lesson How to Perform Repetitive Tasks in Python Based on Conditions.
Example of Compound Assignment Operators
numbers = [1, 2, 3, 4, 5]
total = 0
for num in numbers:
total += num
print("total:", total) # 15
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