how to send an array over a socket in python

Sockets are byte streams, so ideal is to write your protocol (read this)

This is a basic example without protocol and you should care about buffer -> recv(). If it is too small, your data will be chopped off. That's why you should implement a protocol, if you send unknown size of data.

Client:

import socket, pickle

HOST = 'localhost'
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
arr = ([1,2,3,4,5,6],[1,2,3,4,5,6])
data_string = pickle.dumps(arr)
s.send(data_string)

data = s.recv(4096)
data_arr = pickle.loads(data)
s.close()
print 'Received', repr(data_arr)

Server:

import socket

HOST = 'localhost'
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
while 1:
    data = conn.recv(4096)
    if not data: break
    conn.send(data)
conn.close()

I solved this problem using json (since I heard pickle is unsafe)

client:

import json
...
arr1 = [1,2,3]
arr2 = [4,5,6]
someVar = 7
data = json.dumps({"a": arr1, "b": arr2, "c": someVar})
socket.send(data.encode())

server:

import json
...
data = socket.recv(1024)
data = json.loads(data.decode())
arr = data.get("a")
var = data.get("c")

Here we deserialize the json string, using data.get("a") which you can interpret as data.a

I solved this issue by going over each item in the array, adding it to a single string, but with a significant character, such as a greek letter or some other uncommon character, then sending that string over the socket, then splitting the recieved string up back into an array on the other side, and removing all of the 'delimiter' items in the new array.

For Example, The Client side

for item in myArray:
        print("item: ", item)
        myArrayString= myArrayString+ str(item) + "Δ"
    print(myArrayString)
    myServer.send((myArrayString).encode())

and then on the Server:

files = myconnection.recv(50000)
        files = files.decode()
        myArray = files.split('Δ')

        for myItem in myArray:
            print(myItem)
        print("End Of Items in Array")

hope this helps! feel free to ask if you need anything clarified! : )