Python – Convert Octal String to Integer

In this tutorial, we will look at how to convert an octal number (as a string) to an integer in Python with the help of examples.

How to convert octal string to integer in Python?

You can use the Python built-in int() function to convert an octal string to an integer in Python. Pass the oct string as an argument. The following is the syntax –

# oct string to int
int(oct_str, 8)

The int() function also takes an optional argument, base to identify the base of the value passed. For example, use 16 as the base to convert hex string, use 8 as the base for an octal string, etc.

Although, the int() function is capable of inferring the base from the string passed, it’s a good practice to explicitly specify the base.

Examples

Let’s look at some examples of using the above syntax to convert an oct string to an int.

Oct string with prefix to int

Let’s convert an octal number (as a string) with the prefix '0o' to an integer using the int() function.

# oct string representing 1024
oct_str = '0o2000'
# oct to int
num = int(oct_str, 8)
print(num)

Output:

1024

Here we have an oct string representing the number 1024 with the prefix '0o'. We use the int() function to convert the oct string to an integer. You can see that we get 1024 as the output.

Oct string without prefix to int

Let’s now try to convert an oct string without a prefix to int using the int() function. You don’t need to change any arguments as the int() function is capable to handle the oct string irrespective of the presence of the prefix.

# oct string representing 1024 without '0o' prefix
oct_str = '2000'
# oct to int
num = int(oct_str, 8)
print(num)

Output:

1024

Here we pass the oct string without the '0o' prefix to the int() function with base as 8. We get the same output as above.

For more on the Python int() function, refer to its documentation.

You might also be interested in –

• Python – Convert Hexadecimal String to Integer
• Convert int to bytes in Python
• Python – Convert Integer to Binary String