Python offers a shorthand for updating variables. When you have a number saved in a variable and want to add to the current value of the variable, you can use the += (plus-equals) operator.

# First we have a variable with a number saved
number_of_miles_hiked = 12

# Then we need to update that variable
# Let's say we hike another two miles today
number_of_miles_hiked += 2

# The new value is the old value
# Plus the number after the plus-equals
print(number_of_miles_hiked)
# Prints 14

Above, we keep a running count of the number of miles a person has gone hiking over time. Instead of recalculating from the start, we keep a grand total and update it when we’ve gone hiking further.

The plus-equals operator also can be used for string concatenation, like so:

hike_caption = "What an amazing time to walk through nature!"

# Almost forgot the hashtags!
hike_caption += " #nofilter"
hike_caption += " #blessed"

We create the social media caption for the photograph of nature we took on our hike, but then update the caption to include important social media tags we almost forgot.