[Python] socket send

Try putting a 'b' before the constant string that you want to send:
<class 'bytes'>

or use something like this to convert non constant strings (with only
ASCII characters) into bytes:
'A non-constant string : 12 '
<class 'str'>
b'A non-constant string : 12 '

You could also use struct.pack , that in python 3.x returns bytes and
not strings. In this case you need to specify the size of the string
(extra
bytes are zero-filled):

import struct
b'A non-constant string : 12 \x00\x00\x00'



Ciao
-----
FB

It's true. In python '...' literals are for strings ('str' type) and
b'...' literals are for binary data (bytes type).

Sockets' send() and recv() need binary data ('bytes' objects).
What???

'str' type in Python 3.x IS NOT a type of "non-constant" strings and
IS NOT a type of strings "with only ASCII characters"!

'str' type in Python 3.x *is* the type of immutable ('constant') and
Unicode character (Unicode, not only ASCII) strings. It's the same what
'unicode' type in Python 2.x.

'bytes' type objects in Python 3.x are also immutable. They are good
for binary data (also text data encoded to binary data; see below).

'bytearray' type objects are like 'bytes', but mutable (like e. g.
lists).
What for all that weird actions???

* Simply do:

bytes_object = str_object.encode(<encoding>)
or
bytes_object = bytes(str_object, <encoding>)

-- where <encoding> could be e.g. 'ascii', 'utf-8', 'iso-8859-1' etc.;
using the former method, you can omit this argument -> then default
encoding will be used (usualy 'utf-8').

* As easily as that, you can convert bytes to str:

str_object = bytes_object.decode(<encoding>)
or
str_object = str(bytes_object, <encoding>)

* Some examples:
'What makes you think she is a witch?'
b'What makes you think she is a witch?'
b'What makes you think she is a witch?'
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: string argument without an encoding
b'What makes you think she is a witch?'
'What makes you think she is a witch?'
'What makes you think she is a witch?'
'What makes you think she is a witch?'
"b'What makes you think she is a witch?'"
[^ note this]

Cheers,

*j

... unfortunate choice of words and not enough research on my part
here. WHat I meant was: if you want
to send via socket a constant string, use b"..."; if you want to send
via socket a string that you
made out of variables (the "non-constant string" ) then you have to
convert it in bytes. Since I did not
now of the encode method, I tried other solutions, like the one-liner
using ord or using the struct
module. Obviously, encode is better.

My bad :-)

Ciao
-------
FB

"NighterNet" <darkneter at gmail.com> wrote in message
news:55aba832-df6d-455f-bf34-04d37eb061cd at i4g2000prm.googlegroups.com...
Python 3.1 strings are Unicode (think characters not bytes). When writing
to files, sockets, etc. bytes must be used. Unicode strings have an
encode() method, where you can specify an appropriate encoding (ascii,
latin-1, windows-1252, utf-8, etc.):

clientSock.send(buff.encode('ascii'))

When reading from the socket, you can decode() the byte strings back into
Unicode strings.

data = clientSock.recv(1024).decode('ascii')

-Mark

I am not sure how to use struct package.
Here an example for the input:
{id:1,playername:guest,x:100,y:50}
{id:2,playername:tester,x:100,y:50}

struct.pack(? )

If your messages are ASCII, like it seems, forget about struct, which
is for 'binary' message format.
Format the string as you would in 2.6 ( using % or string.format for
instance ) and then use encode
as instructed.

And what is the problem?

*j