# Sum all numbers in a range in Python Last updated: Jul 4, 2022 Photo from Unsplash

## Sum all numbers in a range in Python#

To sum all numbers in a range:

1. Use the `range()` class to get a range of numbers.
2. Pass the `range` object to the `sum()` function.
3. The `sum()` function will return the sum of the integers in the range.
main.py
```Copied!```start = 1
stop = 5

# ✅ sum all integers in range()

total = sum(range(start, stop))

print(total)  # 👉️ 10 (1 + 2 + 3 + 4)

# --------------------------------------

# ✅ sum all integers in range with step()

step = 2

total_2 = sum(range(start, stop, step))

print(total_2)  # 👉️ 4 (1 + 3)
``````

We used the `range()` class to get a range of numbers.

The range class is commonly used for looping a specific number of times in `for` loops and takes the following arguments:

NameDescription
`start`An integer representing the start of the range (defaults to `0`)
`stop`Go up to, but not including the provided integer
`step`Range will consist of every N numbers from `start` to `stop` (defaults to `1`)

If you only pass a single argument to the `range()` constructor, it is considered to be the value for the `stop` parameter.

main.py
```Copied!```# 👇️ [0, 1, 2, 3, 4]
print(list(range(5)))

total = sum(range(5))
print(total)  # 👉️ 10
``````
The example shows that if the `start` argument is omitted, it defaults to `0` and if the `step` argument is omitted, it defaults to `1`.

If values for the `start` and `stop` parameters are provided, the `start` value is inclusive, whereas the `stop` value is exclusive.

main.py
```Copied!```# 👇️ [1, 2, 3, 4]
print(list(range(1, 5)))

total = sum(range(1, 5))
print(total)  # 👉️ 10
``````

If the value for the `stop` parameter is lower than the value for the `start` parameter, the range will be empty.

main.py
```Copied!```# 👇️ []
print(list(range(5, 1)))

total = sum(range(5, 1))
print(total)  # 👉️ 0
``````

The `sum` function can be used to calculate the sum of the numbers in the range.

The sum function takes an iterable, sums its items from left to right and returns the total.

The `sum` function takes the following 2 arguments:

NameDescription
iterablethe iterable whose items to sum
startsums the `start` value and the items of the iterable. `sum` defaults to `0` (optional)

If you need to get a range with a step, pass a value for the third argument of the `range()` class.

main.py
```Copied!```start = 1
stop = 5
step = 2

total_2 = sum(range(start, stop, step))

print(total_2)  # 👉️ 4 (1 + 3)

# 👇️ [1, 3]
print(list(range(start, stop, step)))
``````

When the `step` argument is provided, the range will consist of every N numbers from `start` to `stop`.

The value for the `step` argument defaults to `1`.

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