Integer array to string in Python

Question

I have an array of integer, and I need to transform it into string.

[1,2,3,4] => '\x01\x02\x03\x04'

What function can I use for it? I tried with str(), but it returns '1234'.

string = ""
for val in [1,2,3,4]:
    string += str(val) # '1234'

Answer 1

''.join([chr(x) for x in [1, 2, 3, 4]])

Answer 2

You can convert a list of small numbers directly to a bytearray:

If it is an iterable, it must be an iterable of integers in the range 0 <= x < 256, which are used as the initial contents of the array.

And you can convert a bytearray directly to a str (2.x) or bytes (3.x, or 2.6+).

In fact, in 3.x, you can even convert the list straight to bytes without going through bytearray:

constructor arguments are interpreted as for bytearray().

So:

str(bytearray([1,2,3,4])) # 2.6-2.7 only
bytes(bytearray([1,2,3,4])) # 2.6-2.7, 3.0+
bytes([1,2,3,4]) # 3.0+ only

If you really want a string in 3.x, as opposed to a byte string, you need to decode it:

bytes(bytearray([1,2,3,4])).decode('ascii')

See Binary Sequence Types in the docs for more details.