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Python中简单数组查找上的小循环的性能问题_Python_C++_Arrays_Performance - Fatal编程技术网

Python中简单数组查找上的小循环的性能问题

Python中简单数组查找上的小循环的性能问题,python,c++,arrays,performance,Python,C++,Arrays,Performance,为什么简单循环和/或简单数组查找在Python中如此缓慢 特别地,在下面的例子中,Python(使用 pypy)比C++慢了9倍()。解释性能损失的技术原因是什么?它是机器代码中Python循环的实现吗?编译器使用的优化有什么不同?内存管理?还是别的什么 Python代码: # File: timing.py import sys T = [ \ [ 0, 6, 7, 7, 7, 8, 6, 7, 8,19,20, 7, 7, 7, 7, 7, 7,21,22,19,20,21,

为什么简单循环和/或简单数组查找在Python中如此缓慢

特别地,在下面的例子中,Python(使用<代码> pypy)比C++慢了9倍(<<代码> -O2 >)。解释性能损失的技术原因是什么?它是机器代码中Python循环的实现吗?编译器使用的优化有什么不同?内存管理?还是别的什么

Python代码:

# File: timing.py
import sys
T = [ \
        [ 0, 6, 7, 7, 7, 8, 6, 7, 8,19,20, 7, 7, 7, 7, 7, 7,21,22,19,20,21,22,29, 7, 7, 7, 7, 7,29,35,36, 7, 7, 7,35,36, 7, 7,], \
        [ 9, 7,10, 7, 7, 7, 1, 7,23, 7, 7, 1,23, 7, 7, 7, 7, 7, 7, 9,10,30,31, 7, 9,10,30,31, 7,23, 7, 7,23, 7, 7,30,31,30,31,], \
        [ 7, 7, 2,11,12, 7, 7, 7, 7, 7, 7,11,12,24,25,26,27, 7, 7, 7, 7, 7, 7, 7,24,25,26,27,32, 7, 7, 7,32,37,38, 7, 7,37,38,], \
        [13, 7,14, 7, 7, 7, 3, 7,28, 7, 7, 3,28, 7, 7, 7, 7, 7, 7,13,14,33,34, 7,13,14,33,34, 7,28, 7, 7,28, 7, 7,33,34,33,34,], \
        [15, 7,16, 7, 7, 7, 7, 7, 4, 7, 7, 7, 4, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [17, 7,18, 7, 7, 7, 7, 7, 5, 7, 7, 7, 5, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [19, 7,20, 7, 7, 7, 6, 7,29, 7, 7, 6,29, 7, 7, 7, 7, 7, 7,19,20,35,36, 7,19,20,35,36, 7,29, 7, 7,29, 7, 7,35,36,35,36,], \
        [ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [21, 7,22, 7, 7, 7, 7, 7, 8, 7, 7, 7, 8, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 9, 1, 7, 7, 7,23, 1, 7,23, 9,10, 7, 7, 7, 7, 7, 7,30,31, 9,10,30,31,23, 7, 7, 7, 7, 7,23,30,31, 7, 7, 7,30,31, 7, 7,], \
        [ 7, 7,10, 1,23, 7, 7, 7, 7, 7, 7, 1,23, 9,10,30,31, 7, 7, 7, 7, 7, 7, 7, 9,10,30,31,23, 7, 7, 7,23,30,31, 7, 7,30,31,], \
        [24, 7,25, 7, 7, 7,11, 7,32, 7, 7,11,32, 7, 7, 7, 7, 7, 7,24,25,37,38, 7,24,25,37,38, 7,32, 7, 7,32, 7, 7,37,38,37,38,], \
        [26, 7,27, 7, 7, 7, 7, 7,12, 7, 7, 7,12, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [13, 3, 7, 7, 7,28, 3, 7,28,13,14, 7, 7, 7, 7, 7, 7,33,34,13,14,33,34,28, 7, 7, 7, 7, 7,28,33,34, 7, 7, 7,33,34, 7, 7,], \
        [ 7, 7,14, 3,28, 7, 7, 7, 7, 7, 7, 3,28,13,14,33,34, 7, 7, 7, 7, 7, 7, 7,13,14,33,34,28, 7, 7, 7,28,33,34, 7, 7,33,34,], \
        [15, 7, 7, 7, 7, 4, 7, 7, 4, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 7, 7,16, 7, 4, 7, 7, 7, 7, 7, 7, 7, 4, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [17, 7, 7, 7, 7, 5, 7, 7, 5, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 7, 7,18, 7, 5, 7, 7, 7, 7, 7, 7, 7, 5, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [19, 6, 7, 7, 7,29, 6, 7,29,19,20, 7, 7, 7, 7, 7, 7,35,36,19,20,35,36,29, 7, 7, 7, 7, 7,29,35,36, 7, 7, 7,35,36, 7, 7,], \
        [ 7, 7,20, 6,29, 7, 7, 7, 7, 7, 7, 6,29,19,20,35,36, 7, 7, 7, 7, 7, 7, 7,19,20,35,36,29, 7, 7, 7,29,35,36, 7, 7,35,36,], \
        [21, 7, 7, 7, 7, 8, 7, 7, 8, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 7, 7,22, 7, 8, 7, 7, 7, 7, 7, 7, 7, 8, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [30, 7,31, 7, 7, 7, 7, 7,23, 7, 7, 7,23, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [24,11, 7, 7, 7,32,11, 7,32,24,25, 7, 7, 7, 7, 7, 7,37,38,24,25,37,38,32, 7, 7, 7, 7, 7,32,37,38, 7, 7, 7,37,38, 7, 7,], \
        [ 7, 7,25,11,32, 7, 7, 7, 7, 7, 7,11,32,24,25,37,38, 7, 7, 7, 7, 7, 7, 7,24,25,37,38,32, 7, 7, 7,32,37,38, 7, 7,37,38,], \
        [26, 7, 7, 7, 7,12, 7, 7,12, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 7, 7,27, 7,12, 7, 7, 7, 7, 7, 7, 7,12, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [33, 7,34, 7, 7, 7, 7, 7,28, 7, 7, 7,28, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [35, 7,36, 7, 7, 7, 7, 7,29, 7, 7, 7,29, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [30, 7, 7, 7, 7,23, 7, 7,23, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 7, 7,31, 7,23, 7, 7, 7, 7, 7, 7, 7,23, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [37, 7,38, 7, 7, 7, 7, 7,32, 7, 7, 7,32, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [33, 7, 7, 7, 7,28, 7, 7,28, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 7, 7,34, 7,28, 7, 7, 7, 7, 7, 7, 7,28, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [35, 7, 7, 7, 7,29, 7, 7,29, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 7, 7,36, 7,29, 7, 7, 7, 7, 7, 7, 7,29, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [37, 7, 7, 7, 7,32, 7, 7,32, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
        [ 7, 7,38, 7,32, 7, 7, 7, 7, 7, 7, 7,32, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,], \
            ]

M = range(39)
idempotents = [0,2,6,7,8,9,11,12,14,16,17,19,21,25,27]
omega = [0,7,2,7,7,7,6,7,8,9,7,11,12,7,14,7,16,17,7,19,7,21,7,7,7,25,7,27,7,7,7,7,7,7,7,7,7,7,7]

def check():
    for e in idempotents:
        for x in M:
            ex = T[e][x]
            for s in M:
                es = T[e][s]
                for f in idempotents:
                    exf = T[ex][f]
                    esf = T[es][f]
                    for y in M:
                        exfy = omega[T[exf][y]]
                        for t in M:
                            tesf = omega[T[t][esf]]
                            if T[T[exfy][exf]][tesf] != T[T[exfy][esf]][tesf]:
                                return 0
    return 1
sys.exit(check())

C++代码(由于新的数组初始化和迭代语法需要C++ 11):< /P>

//文件:timing.cc
//通过“g++-std=c++11-O2 timing.cc”编译
//通过“time./a.out”运行
#包括
#包括
int main(int,char**){
常数大小N=39;
typedef无符号元素;
常数std::向量T{{
{{ 0, 6, 7, 7, 7, 8, 6, 7, 8,19,20, 7, 7, 7, 7, 7, 7,21,22,19,20,21,22,29, 7, 7, 7, 7, 7,29,35,36, 7, 7, 7,35,36, 7, 7,}}, 
{{ 9, 7,10, 7, 7, 7, 1, 7,23, 7, 7, 1,23, 7, 7, 7, 7, 7, 7, 9,10,30,31, 7, 9,10,30,31, 7,23, 7, 7,23, 7, 7,30,31,30,31,}}, 
{{ 7, 7, 2,11,12, 7, 7, 7, 7, 7, 7,11,12,24,25,26,27, 7, 7, 7, 7, 7, 7, 7,24,25,26,27,32, 7, 7, 7,32,37,38, 7, 7,37,38,}}, 
{{13, 7,14, 7, 7, 7, 3, 7,28, 7, 7, 3,28, 7, 7, 7, 7, 7, 7,13,14,33,34, 7,13,14,33,34, 7,28, 7, 7,28, 7, 7,33,34,33,34,}}, 
{{15, 7,16, 7, 7, 7, 7, 7, 4, 7, 7, 7, 4, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{17, 7,18, 7, 7, 7, 7, 7, 5, 7, 7, 7, 5, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{19, 7,20, 7, 7, 7, 6, 7,29, 7, 7, 6,29, 7, 7, 7, 7, 7, 7,19,20,35,36, 7,19,20,35,36, 7,29, 7, 7,29, 7, 7,35,36,35,36,}}, 
{{ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{21, 7,22, 7, 7, 7, 7, 7, 8, 7, 7, 7, 8, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 9, 1, 7, 7, 7,23, 1, 7,23, 9,10, 7, 7, 7, 7, 7, 7,30,31, 9,10,30,31,23, 7, 7, 7, 7, 7,23,30,31, 7, 7, 7,30,31, 7, 7,}}, 
{{ 7, 7,10, 1,23, 7, 7, 7, 7, 7, 7, 1,23, 9,10,30,31, 7, 7, 7, 7, 7, 7, 7, 9,10,30,31,23, 7, 7, 7,23,30,31, 7, 7,30,31,}}, 
{{24, 7,25, 7, 7, 7,11, 7,32, 7, 7,11,32, 7, 7, 7, 7, 7, 7,24,25,37,38, 7,24,25,37,38, 7,32, 7, 7,32, 7, 7,37,38,37,38,}}, 
{{26, 7,27, 7, 7, 7, 7, 7,12, 7, 7, 7,12, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{13, 3, 7, 7, 7,28, 3, 7,28,13,14, 7, 7, 7, 7, 7, 7,33,34,13,14,33,34,28, 7, 7, 7, 7, 7,28,33,34, 7, 7, 7,33,34, 7, 7,}}, 
{{ 7, 7,14, 3,28, 7, 7, 7, 7, 7, 7, 3,28,13,14,33,34, 7, 7, 7, 7, 7, 7, 7,13,14,33,34,28, 7, 7, 7,28,33,34, 7, 7,33,34,}}, 
{{15, 7, 7, 7, 7, 4, 7, 7, 4, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 7, 7,16, 7, 4, 7, 7, 7, 7, 7, 7, 7, 4, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{17, 7, 7, 7, 7, 5, 7, 7, 5, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 7, 7,18, 7, 5, 7, 7, 7, 7, 7, 7, 7, 5, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{19, 6, 7, 7, 7,29, 6, 7,29,19,20, 7, 7, 7, 7, 7, 7,35,36,19,20,35,36,29, 7, 7, 7, 7, 7,29,35,36, 7, 7, 7,35,36, 7, 7,}}, 
{{ 7, 7,20, 6,29, 7, 7, 7, 7, 7, 7, 6,29,19,20,35,36, 7, 7, 7, 7, 7, 7, 7,19,20,35,36,29, 7, 7, 7,29,35,36, 7, 7,35,36,}}, 
{{21, 7, 7, 7, 7, 8, 7, 7, 8, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 7, 7,22, 7, 8, 7, 7, 7, 7, 7, 7, 7, 8, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{30, 7,31, 7, 7, 7, 7, 7,23, 7, 7, 7,23, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{24,11, 7, 7, 7,32,11, 7,32,24,25, 7, 7, 7, 7, 7, 7,37,38,24,25,37,38,32, 7, 7, 7, 7, 7,32,37,38, 7, 7, 7,37,38, 7, 7,}}, 
{{ 7, 7,25,11,32, 7, 7, 7, 7, 7, 7,11,32,24,25,37,38, 7, 7, 7, 7, 7, 7, 7,24,25,37,38,32, 7, 7, 7,32,37,38, 7, 7,37,38,}}, 
{{26, 7, 7, 7, 7,12, 7, 7,12, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 7, 7,27, 7,12, 7, 7, 7, 7, 7, 7, 7,12, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{33, 7,34, 7, 7, 7, 7, 7,28, 7, 7, 7,28, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{35, 7,36, 7, 7, 7, 7, 7,29, 7, 7, 7,29, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{30, 7, 7, 7, 7,23, 7, 7,23, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 7, 7,31, 7,23, 7, 7, 7, 7, 7, 7, 7,23, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{37, 7,38, 7, 7, 7, 7, 7,32, 7, 7, 7,32, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{33, 7, 7, 7, 7,28, 7, 7,28, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 7, 7,34, 7,28, 7, 7, 7, 7, 7, 7, 7,28, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{35, 7, 7, 7, 7,29, 7, 7,29, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 7, 7,36, 7,29, 7, 7, 7, 7, 7, 7, 7,29, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{37, 7, 7, 7, 7,32, 7, 7,32, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
{{ 7, 7,38, 7,32, 7, 7, 7, 7, 7, 7, 7,32, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
}};
常数std::向量幂等元{{0,2,6,7,8,9,11,12,14,16,17,19,21,25,27};
常数std::向量ω
// File: timing.cc
// Compile via 'g++ -std=c++11 -O2 timing.cc'
// Run via 'time ./a.out'
#include <vector>
#include <cstddef>

int main(int, char **) {
  const size_t N = 39;
  typedef unsigned element_t;
  const std::vector<std::vector<element_t>> T{{
     {{ 0, 6, 7, 7, 7, 8, 6, 7, 8,19,20, 7, 7, 7, 7, 7, 7,21,22,19,20,21,22,29, 7, 7, 7, 7, 7,29,35,36, 7, 7, 7,35,36, 7, 7,}}, 
     {{ 9, 7,10, 7, 7, 7, 1, 7,23, 7, 7, 1,23, 7, 7, 7, 7, 7, 7, 9,10,30,31, 7, 9,10,30,31, 7,23, 7, 7,23, 7, 7,30,31,30,31,}}, 
     {{ 7, 7, 2,11,12, 7, 7, 7, 7, 7, 7,11,12,24,25,26,27, 7, 7, 7, 7, 7, 7, 7,24,25,26,27,32, 7, 7, 7,32,37,38, 7, 7,37,38,}}, 
     {{13, 7,14, 7, 7, 7, 3, 7,28, 7, 7, 3,28, 7, 7, 7, 7, 7, 7,13,14,33,34, 7,13,14,33,34, 7,28, 7, 7,28, 7, 7,33,34,33,34,}}, 
     {{15, 7,16, 7, 7, 7, 7, 7, 4, 7, 7, 7, 4, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{17, 7,18, 7, 7, 7, 7, 7, 5, 7, 7, 7, 5, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{19, 7,20, 7, 7, 7, 6, 7,29, 7, 7, 6,29, 7, 7, 7, 7, 7, 7,19,20,35,36, 7,19,20,35,36, 7,29, 7, 7,29, 7, 7,35,36,35,36,}}, 
     {{ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{21, 7,22, 7, 7, 7, 7, 7, 8, 7, 7, 7, 8, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 9, 1, 7, 7, 7,23, 1, 7,23, 9,10, 7, 7, 7, 7, 7, 7,30,31, 9,10,30,31,23, 7, 7, 7, 7, 7,23,30,31, 7, 7, 7,30,31, 7, 7,}}, 
     {{ 7, 7,10, 1,23, 7, 7, 7, 7, 7, 7, 1,23, 9,10,30,31, 7, 7, 7, 7, 7, 7, 7, 9,10,30,31,23, 7, 7, 7,23,30,31, 7, 7,30,31,}}, 
     {{24, 7,25, 7, 7, 7,11, 7,32, 7, 7,11,32, 7, 7, 7, 7, 7, 7,24,25,37,38, 7,24,25,37,38, 7,32, 7, 7,32, 7, 7,37,38,37,38,}}, 
     {{26, 7,27, 7, 7, 7, 7, 7,12, 7, 7, 7,12, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{13, 3, 7, 7, 7,28, 3, 7,28,13,14, 7, 7, 7, 7, 7, 7,33,34,13,14,33,34,28, 7, 7, 7, 7, 7,28,33,34, 7, 7, 7,33,34, 7, 7,}}, 
     {{ 7, 7,14, 3,28, 7, 7, 7, 7, 7, 7, 3,28,13,14,33,34, 7, 7, 7, 7, 7, 7, 7,13,14,33,34,28, 7, 7, 7,28,33,34, 7, 7,33,34,}}, 
     {{15, 7, 7, 7, 7, 4, 7, 7, 4, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 7, 7,16, 7, 4, 7, 7, 7, 7, 7, 7, 7, 4, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7,15,16, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{17, 7, 7, 7, 7, 5, 7, 7, 5, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 7, 7,18, 7, 5, 7, 7, 7, 7, 7, 7, 7, 5, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7,17,18, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{19, 6, 7, 7, 7,29, 6, 7,29,19,20, 7, 7, 7, 7, 7, 7,35,36,19,20,35,36,29, 7, 7, 7, 7, 7,29,35,36, 7, 7, 7,35,36, 7, 7,}}, 
     {{ 7, 7,20, 6,29, 7, 7, 7, 7, 7, 7, 6,29,19,20,35,36, 7, 7, 7, 7, 7, 7, 7,19,20,35,36,29, 7, 7, 7,29,35,36, 7, 7,35,36,}}, 
     {{21, 7, 7, 7, 7, 8, 7, 7, 8, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 7, 7,22, 7, 8, 7, 7, 7, 7, 7, 7, 7, 8, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7,21,22, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{30, 7,31, 7, 7, 7, 7, 7,23, 7, 7, 7,23, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{24,11, 7, 7, 7,32,11, 7,32,24,25, 7, 7, 7, 7, 7, 7,37,38,24,25,37,38,32, 7, 7, 7, 7, 7,32,37,38, 7, 7, 7,37,38, 7, 7,}}, 
     {{ 7, 7,25,11,32, 7, 7, 7, 7, 7, 7,11,32,24,25,37,38, 7, 7, 7, 7, 7, 7, 7,24,25,37,38,32, 7, 7, 7,32,37,38, 7, 7,37,38,}}, 
     {{26, 7, 7, 7, 7,12, 7, 7,12, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 7, 7,27, 7,12, 7, 7, 7, 7, 7, 7, 7,12, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7,26,27, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{33, 7,34, 7, 7, 7, 7, 7,28, 7, 7, 7,28, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{35, 7,36, 7, 7, 7, 7, 7,29, 7, 7, 7,29, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{30, 7, 7, 7, 7,23, 7, 7,23, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 7, 7,31, 7,23, 7, 7, 7, 7, 7, 7, 7,23, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7,30,31, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{37, 7,38, 7, 7, 7, 7, 7,32, 7, 7, 7,32, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{33, 7, 7, 7, 7,28, 7, 7,28, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 7, 7,34, 7,28, 7, 7, 7, 7, 7, 7, 7,28, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7,33,34, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{35, 7, 7, 7, 7,29, 7, 7,29, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 7, 7,36, 7,29, 7, 7, 7, 7, 7, 7, 7,29, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7,35,36, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{37, 7, 7, 7, 7,32, 7, 7,32, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
     {{ 7, 7,38, 7,32, 7, 7, 7, 7, 7, 7, 7,32, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7,37,38, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,}}, 
  }};

  const std::vector<element_t> idempotents{{0,2,6,7,8,9,11,12,14,16,17,19,21,25,27}};
  const std::vector<element_t> omega{{0,7,2,7,7,7,6,7,8,9,7,11,12,7,14,7,16,17,7,19,7,21,7,7,7,25,7,27,7,7,7,7,7,7,7,7,7,7,7}};

  element_t ex, es, exf, esf, exfy, tesf;
  for(auto e: idempotents) {
    for(size_t x = 0; x < N; ++x) {
      ex = T[e][x];
      for(size_t s = 0; s < N; ++s) {
        es = T[e][s];
        for(auto f: idempotents) {
          exf = T[ex][f];
          esf = T[es][f];
          for(size_t y = 0; y < N; ++y) {
            exfy = omega[T[exf][y]];
            for(size_t t = 0; t < N; ++t) {
              tesf = omega[T[t][esf]];
              if(T[T[exfy][exf]][tesf] != T[T[exfy][esf]][tesf])
                return 0;
            }}}}}}
  return 1;
}
for e in idempotents:
    for x in M:
        ex = T[e][x]
T[idempotents]
for e in idempotents:
    for x in M:
        ex = T[e][x]
        for s in M:
            es = T[e][s]
es=ex
for f in idempotents:
    exf = T[ex][f]
    esf = T[es][f]
T[T[idempotents]]
print T[T[idempotents]].shape
>> (15, 39, 39)
exf = T[T[idempotents]]
esf = exf
Ti = T[idempotents]  # T[e][x] == T[e][s] by loop definition
TTi = T[Ti]  # T[T[e][x]]
TTi.shape = -1 , 39  # bring first index back into shape
exf = TTi[:, idempotents]  # T[T[e][x]][f]
esf = exf  # T[T[e][s]][f] == T[T[e][x]][f] by loop definition
Texf = T[exf].ravel()
exfy = omega[Texf]
TTexf = T.T[exf].ravel()  # tesf = omega[T[t][esf]] # since I cannot index fast along t I use the transpose of T
tesf = omega[TTexf]