1:
2:
3:
4:
5:

>>> sigma = (4, 3, 2, 1)
>>> spam = [’s’, ’p’, ’a’, ’m’]
>>> apply(sigma, spam)
>>> spam
[’m’, ’a’, ’p’, ’s’]

1:
2:
3:
4:
5:

 File "<pyshell#12>", line 1, in <module>
    print(inv(s))
  File "<pyshell#3>", line 4, in inv
    inverse[p] = i
IndexError: list assignment index out of range

1:
2:
3:
4:

def apply(s, lst):
      s=[s[t[i]-1] for i in range(len(t))]
      return s

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:

apply(sigma, spam)
Traceback (most recent call last):
  File "<pyshell#21>", line 1, in <module>
    apply(sigma,spam)
  File "C:\Users\Name\AppData\Local\Programs\Python\Python35-32\examples\permutationas.py", line 2, in apply
    s=[s[lst[i]-1] for i in range(len(lst))]
  File "C:\Users\Name\AppData\Local\Programs\Python\Python35-32\examples\permutationas.py", line 2, in <listcomp>
    s=[s[lst[i]-1] for i in range(len(lst))]
TypeError: unsupported operand type(s) for -: 'str' and 'int'

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:

def inv(perm):
	inverse = [0] * len(perm)
	for i, p in enumerate(perm):
		inverse[p-1] = i+1
	return inverse

def compose(s, t):
	s=[s[t[i]-1] for i in range(len(t))]
	return s

def order(s):
	counter = 1
	current = compose(s, s)
	while any(s[i] != current[i] for i in range(len(s))):
		counter += 1
		current = compose(current, s)
	return counter

sigma = [2, 1, 4, 3]
inv(sigma) #[2, 1, 4, 3]
order(sigma) #2