NoneType object cannot be interpreted as an integer

NoneType object cannot be interpreted as an integer #

The Python "TypeError: 'NoneType' object cannot be interpreted as an integer" occurs when we pass a None value to a function that expects an integer argument. To solve the error, track down where the None value comes from and pass an integer to the function.

Here is an example of how the error occurs.

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# ⛔️ TypeError: 'tuple' object cannot be interpreted as an integer
for i in range(None):
    print(i)

We passed a None value to the range() constructor which expects to get called with an integer.

The most common source of a None value (other than an explicit assignment) is a function that doesn't return anything.

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# 👇️ this function returns None
def get_num(a, b):
    print(a + b)


# ⛔️ TypeError: 'NoneType' object cannot be interpreted as an integer
for i in range(get_num(5, 5)):
    print(i)

Notice that our get_num function doesn't explicitly return a value, so it implicitly returns None.

The "TypeError: 'NoneType' object cannot be interpreted as an integer" occurs for multiple reasons:

1. Having a function that doesn't return anything (returns None implicitly).
2. Explicitly setting a variable to None.
3. Assigning a variable to the result of calling a built-in function that doesn't return anything.
4. Having a function that only returns a value if certain condition is met.

You can check if the variable doesn't store a None value before calling the function.

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my_num = None

if my_num is not None:
    for i in range(my_num):
        print(i)
else:
    print('variable is None')

The if block will run only if the my_num variable does not store a None value, otherwise the else block runs.

Another common cause of the error is having a function that returns a value only if a condition is met.

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def get_num(a):
    if a > 100:
        return a


result = get_num(5)

print(result)  # 👉️ None

The if statement in the get_num function is only ran if the passed in argument is greater than 100.

To solve the error in this scenario, you either have to check if the function didn't return None or return a default value if the condition is not met.

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def get_num(a):
    if a > 100:
        return a
    return 0 # 👈️ returns 0 if condition not met


result = get_num(5)

print(result)  # 👉️ 0

Now the function is guaranteed to return a value regardless if the condition is met.