I wrote an application with Nim and discovered that an application with the
same logic and data structures written in Python has a better execution speed
than the Nim version.
I was trying to find out about the reason why Nim has a larger execution speed
than Python. I isolated some code and tested two small and equivalent Python
and Nim programs.
For a loop count of 100000 Python takes 1.0 sec and Nim takes 1.8 sec This
speed ratio corresponds to the speed ratio in the real application.
I use Python version 2.7.3 and Nim compiler version 0.13.0 I compiled Nim with
with -d:release option.
I'd like to know what is the reason why in this case Python beats Nim in
execution speed.
Here are the both programs. The problem is the proc "do_something"
# Nim example to test execution speed against a Python version
import times, os
var board: seq[char] = @['0', 'p', '.', 'p', 'P', '.', 'p', 'P', '.', 'p',
'.', 'p', 'P', '.', 'p']
const NE: seq[int] = @[8, 2, 13, 4, 5, 7, 8, 3, 9, 12, 7, 8, 3, 9, 12]
const Directions = [NE, NE, NE, NE] # for short: in real application the
array elements differ
proc do_something(board: seq[char]): seq[char] =
var res: seq[char] = @[]
for i, p in board:
for d in Directions:
res.add board[d[i]]
return res
let t0 = cpuTime()
var res: seq[char]
let count = 100000
for i in 1..count:
res = do_something(board)
let t1 = cpuTime()
echo "***** Time elapsed for Nim: ", $(t1 - t0), " Counts: ", $count
##echo res.repr
# Python example to test execution speed against a Nim version
import time, sys
board = ['0', 'p', '.', 'p', 'P', '.', 'p', 'P', '.', 'p', '.', 'p', 'P',
'.', 'p']
NE = [8, 2, 13, 4, 5, 7, 8, 3, 9, 12, 7, 8, 3, 9, 12]
directions = [NE, NE, NE, NE] # for short: in real application the array
elements differ
def do_something(board):
res = []
for i, p in enumerate(board):
for d in directions:
res.append(board[d[i]])
return res
t0 = time.time()
res = []
count = 100000
for i in range(1, count):
res = do_something(board)
t1 = time.time()
print("***** Time elapsed for Python: ", str(t1 - t0)), " Counts: ",
str(count)
##print res
