Convert python byte "array" to int "array

Question

This is my first code in python and I have this issue:

I'm reading a binary file as:

def read_file(file):
    with open(file, "rb") as f:
        frame = f.read()
        print(type(frame)) #out = <class 'bytes'>
        return frame

I need to convert all the vector to int values instead using them as bytes.

After printing I get something like this:

print(frame[0:10])
b'\xff\xff\xff\xffXabccc'

However if I print passing one position only I get this:(the integer values are correct, but I just get them using the function print)

print(frame[0])
255    
print(frame[1])
255
print(frame[2])
255
print(frame[3])
255
print(frame[4])
88
print(frame[5])
97
print(frame[6])
98
print(frame[7])
99
print(frame[8])
99
print(frame[9])
99
print(frame[10])
98

The question is: How can I convert all the positions of my array in one step? I would like to run the code

print(frame[0:10])

and get something like

[255, 255, 255, 255, 88, 97, 98, 99 ,99, 99, 98]

Answer 1

Note: this solution only works for Python 3. For Python 2 solution please see Scott Hunter's answer.

You could do this using a list comprehension:

In [1]: frame = b'\xff\xff\xff\xffXabccc'

In [2]: int_values = [x for x in frame]

In [3]: print(int_values)
[255, 255, 255, 255, 88, 97, 98, 99, 99, 99]

To confirm that these are indeed stored as integer values which you can work with:

In [4]: print([type(x) for x in int_values])
[<class 'int'>, <class 'int'>, <class 'int'>, <class 'int'>, <class 'int'>, 
<class 'int'>, <class 'int'>, <class 'int'>, <class 'int'>, <class 'int'>]

Answer 2

The simplest, and most obvious way to do it, is to pass the frame object to the list constructor. No list comprehension is needed for this:

>>> frame = b'\xff\xff\xff\xffXabccc'
>>> list(frame)
[255, 255, 255, 255, 88, 97, 98, 99, 99, 99]

Answer 3

One solution for python2 or 3 is:

list(bytearray(frame))

Answer 4

If you want to use a list of integer values, and not just print them, you could use:

[ord(x) for x in frame]