# Difference between revisions of "Python:Accumulate over a File with Multiple Variables"

In these examples we accumulate more than one value. We still only need one loop - we just do more work in each.

## Average population

Calculate the average population size for the countries of the world.

Print the total population divided by the number of countries.

Recall that there are three steps:

• Declare and initialise your accumulators before the loop

starts.

```long totPop = 0;
int count = 0;```
• Increment the accumulator inside the loop.
```totPop += pop
count++;```
• Use the result - in this case print it, after the loop.
`     System.out.println(totPop/count);`
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## Is 3 million the median?

Show the number of countries with a population more than 3000000

Show the number of countries with a population less than 3000000

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## USA and the world

Show the GDP of "United States" as a percentage of the world GDP.

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