i cannot find a way to append a bytes string to a bytearray other than += operator.
is that the way it has to be done? bytearray.append() gives an error exception message saying it wants an int. apparently it only takes one at a time:
Output:
>>> ab=bytearray(b'foobar')
>>> ab.append(120)
>>> ab
bytearray(b'foobarx')
>>> ab.append(121,122)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: append() takes exactly one argument (2 given)
>>> ab.append([121,122])
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'list' object cannot be interpreted as an integer
>>> ab.append(121)
>>> ab.append(122)
>>> ab
bytearray(b'foobarxyz')
>>>
It is just like a list. append() for adding 1 value, extend() for adding many.
x = bytearray(b"bytes")
x.extend(b" and more bytes")
print(x)
Output:
bytearray(b'bytes and more bytes')
thank you. i was thinking of a string, such as bytearray, as "one" value, so i never thought of .extend().
another way to extend a bytearray is with a slice:
Output:
lt1a/forums/3 /home/forums 13> py
Python 3.8.10 (default, Nov 14 2022, 12:59:47)
[GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> x = bytearray(b"bytes")
>>> x[len(x):]=b" and more bytes"
>>> print(x)
bytearray(b'bytes and more bytes')
>>>
an even uglier way:
Output:
>>> print(x)
bytearray(b'bytes and more bytes')
>>> x[:]=x+b'and even more bytes'
>>> print(x)
bytearray(b'bytes and more bytesand even more bytes')
>>>
but it's not that much uglier. and i bet these ways can be done with list (and tuples?).
edit:
yeah, i should'a put a space in there.
A bytes object is one object, but so is a list. Both are iterable which is why they can be used as an argument to extend().
(Mar-09-2023, 11:47 PM)deanhystad Wrote: [ -> ]A bytes object is one object, but so is a list. Both are iterable which is why they can be used as an argument to extend().
can i use any iterator that produces the expected types (just about anything for a list) as an argument in .extend()?
Output:
>>> help(bytearray.extend)
Help on method_descriptor:
extend(self, iterable_of_ints, /)
Append all the items from the iterator or sequence to the end of the bytearray.
iterable_of_ints
The iterable of items to append.
what did i do wrong with this? how do i fix it?
Output:
>>>
>>> b=bytearray()
>>> for x in bytearray(b'abc'):
... b.extend(x)
...
Traceback (most recent call last):
File "<stdin>", line 2, in <module>
TypeError: can't extend bytearray with int
>>>
x is a byte. b'abc' is iterable.. You append(byte) and extend(iterable)
so, how do i fix b.extend(x) to make it work, such that b ends up with whatever followed in in the loop control?