# Python program to convert an integer number to octal

### How to convert an integer number to octal string in python :

Python comes with one built-in method* oct()* for converting an *integer* number to *octal* easily. You need to pass one *integer* number to this method. It will *convert the integer to octal* string and returns the value. One thing you should note that the returned octal string is prefixed with *0o*. If the parameter value is not a python int, it should define* __index__()* method that returns an integer.

The syntax of the *oct()* method is as below :

oct(x)

where, *x *is an *integer* number in *binary*, *decimal* or *hexadecimal *format. As explained above, the return value is an octal representation of the integer number *x.*

### Example :

Let’s try *oct()* with a *binary*, *decimal* and *hexadecimal *number.

print("octal representation of 10 is ", oct(10)) print("octal representation of 0xC is ", oct(0xC)) print("octal representation of 0b1010 is ", oct(0b1010))

It will print out the below output :

octal representation of 10 is 0o12 octal representation of 0xC is 0o14 octal representation of 0b1010 is 0o12

### Explanation :

- The first number is decimal
*10*. Octal representation of*10*is*12*. Note that the output is prefixed with*0o*. - The second number is the hexadecimal representation of
*12*. Octal representation of*12*is*14*. So, the result is*0o14*. - The last number is a
*binary*number, which is the binary representation of*10*. This is the reason the output of the first and the third line is the same.

We have tried *oct()* with decimal, *hexadecimal* and *binary* number in the above example. Now, let’s try it with a custom object.

### Find oct() for a custom object :

As mentioned before, for a custom object, we need to implement* __index__()* method, that will return an integer if we want to find the octal value for that object. Let’s do that :

class Student: rank = 73 def __index__(self): return self.rank def __int__(self): return self.rank student = Student() print("oct value of \'student\' is", oct(student))

Output :

oct value of 'student' is 0o111

The above program is also available on Github.

### Conclusion :

octal conversion is easy to implement in python using *oct()* method. Go through the examples above and try to run each one on your machine. If you have any queries, drop a comment below.

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