Python: Why does Python TCP-client receive data so slowly on different compared to same PC?

I have two Python scripts, one TCP-server sending data (at a rate of 1/256 times a second) and a TCP-client receiving data. In the client script, I print the length of the received data. I sent the string "5.8" from the server (thus data of length 3).

When client and server are on the same machine: The length of data received is always 3. When client and server are on different machines in the same local network: The length of data differs but is around 39 (13 times the data sent).

Is there a possible explanation for this discrepancy?

I think the network adding this much latency is unlikely, because the command line "ping" prints at most 2 ms latency with the largest amount of data.

IMPORTANT: I'm using Python 2.7.

import socket

def server():
    host = 'localhost' # replace with IP address in case client is on another machine
    port = 5051

    s = socket.socket()
    s.bind((host, port))
    s.listen(1)
    client_socket, adress = s.accept()

    while True:
        client_socket.send('a'.encode())
    client_socket.close()

if __name__ == '__main__':
    server()

import socket, random, time

def client():
    host = 'localhost' # replace with IP address in case client is on another machine
    port = 5051

    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s_err = s.connect_ex((host, port))
    print(s_err)

    while True:
        data = s.recv(2048)
        print(len(data)) # returns different values depending on client location
    s.close()

if __name__ == '__main__':
    client()

Solution

This is what worked for me: I changed the buffer size of recv() to the number of bytes I want to receive, so in this case

data = s.recv(3)

instead of

data = s.recv(2048)

While on the local machine, something automatically decided that the data can be sent in the smallest packages, while this was not the case when using a local network. So I forced the size of the data sent.

This of course potentially leads to problems of lag. So elsewhere I need to make sure that the remaining data are emptied regularly with a large buffer size, or close the connection if not needed. Not sure about the last one, since I'm still a beginner.