Incorrect throughput value in python - sockets

Question

I am writing a python code to find throughput between server and client. It is based on speedtest.net functionality where I am sending a dummy file to calculate the speed. The problem I am facing is unreliable throughput output. I will appreciate your suggestions on the same. Here is the code.
server.py
import socket
import os
port = 60000
s = socket.socket()
host = socket.gethostname()
s.bind((host, port))
s.listen(5)
print 'Server listening....'
while True:
conn, addr = s.accept()
print 'Got connection from', addr
data = conn.recv(1024)
print('Server received', repr(data))
filename='akki.txt'
b = os.path.getsize(filename)
f = open(filename,'rb')
l = f.read(b)
while (l):
conn.send(l)
l = f.read(b)
f.close()
print('Done sending')
conn.send('Thank you for connecting')
conn.close()
Client.py
import socket
import time
import os
s = socket.socket()
host = socket.gethostname()
port = 60000
t1 = time.time()
s.connect((host, port))
s.send("Hello server!")
with open('received_file', 'wb') as f:
print 'file opened'
t2 = time.time()
while True:
data = s.recv(1024)
if not data:
break
f.write(data)
t3 = time.time()
print data
print 'Total:', t3 - t1
print 'Throughput:', round((1024.0 * 0.001) / (t3 - t1), 3),
print 'K/sec.'
f.close()
print('Successfully received the file')
s.close()
print('connection closed')
Output when sending akki.txt
Server Output
Server listening....
Got connection from ('10.143.47.165', 60902)
('Server received', "'Hello server!'")
Done sending
Client output
file opened
Raw timers: 1503350568.11 1503350568.11 1503350568.11
Total: 0.00499987602234
**Throughput: 204.805 K/sec.**
Successfully received the file
connection closed
Output for ak.zip ( which is bigger file)
Client output
file opened
Total: 0.0499999523163
**Throughput: 20.48 K/sec.**
Successfully received the file
connection closed

Answer 1

Short Answer: you need to take the file size into consideration.
More Details:
Throughput is data/time. Your calculation:
round((1024.0 * 0.001) / (t3 - t1), 3)
Doesn't take the file size into account. Since sending a large file takes more time, 't3-t1' is bigger so your throughput is smaller (same numerator with larger denominator). Try adding the file size to the formula and you should get much more constant results.
Hope this helps.