Compare the speed of appending to a file VS reading everything in memory appending there then rewriting everything.

test_io_write_vs_append.py

"""
## RESULTS ##
# Windows 8.1 + NTFS + SSD:
read_write 6.81500005722
append 6.42299985886

# LinuxMint 15 + ext4 witout journaling + HD
read_write 0.222398996353
append 0.00950384140015
"""
import os
import time as t

# to_write = ["eop" * 10000 + str(i) for i in range(1000)]
to_write = ["eop" * 10 + str(i) for i in range(1000)]
append_filename = "test_append.txt"
rw_filename = "test_read_write.txt"


def append(wop):
    with open(append_filename, 'a') as f:
        f.write(wop)


def read_write(wop):
    text = ""
    if os.path.exists(rw_filename):
        with open(rw_filename, 'r') as f:
            text = f.read()
    with open(rw_filename, 'w') as f:
        f.write(text + wop)


def test(func, f):
    if os.path.exists(f):
        os.remove(f)
    startt = t.time()
    for wop in to_write:
        func(wop)
    return t.time() - startt

print "read_write", test(read_write, rw_filename)
print "append", test(append, append_filename)