Python Decrement Counter with -= Decrement Operator

To decrement a counter in Python, you can use the -= decrement operator and subtract a number from the counter.

i = 0
i -= 1

print(i)

#Output:
-1

The decrement operator is the equivalent of subtracting a number via simple subtraction.

i = 0
i = i - 1

print(i)

#Output:
-1

In Python, counters are frequently used when iterating over an object or keeping track of a count for later use.

There are many useful operators in Python and one such operator which makes counting easy is the decrement operator -=.

You can use the -= to subtract a number to another number and decrement a counter.

For example, if you want to subtract one from a number and decrement a counter, you can do so with the following Python code.

i = 0
i -= 1

print(i)

#Output:
-1

This is the equivalent as using simple subtraction to subtract from a number.

i = 0
i = i + 1

print(i)

#Output:
1

You can subtract any number with the decrement operator including floats.

i = 0
i -= 2

print(i)

i -= 2.0

print(i)

#Output:
-2
-4.0

Increment Counter in Python with Increment Operator +=

If you want to go the other way and increment a counter, then you can use the Python increment operator +=.

The increment operator works the same as the decrement operator.

Below shows you a simple example of how you can increment a counter in Python with the increment operator.

i = 0
i += 1

print(i)

#Output:
1

Hopefully this article has been useful for you to learn how to use the decrement operator and how to decrement a counter in Python.