1. import re
2.  
3. # Fetch input data
4. with open('input.txt') as input_data:
5.     input_data = input_data.readlines()
6.     stacks = [stack.strip('\n') for stack in input_data[:8]]
7.     instructions = [line.strip() for line in input_data[10:]]
8.  
9.     # Create starting stacks as lists/saving lists to dict
10.     one = []
11.     two = []
12.     three = []
13.     four = []
14.     five = []
15.     six = []
16.     seven = []
17.     eight = []
18.     nine = []
19.  
20.     stacks_dict = {
21.         '1':one,
22.         '2':two,
23.         '3':three,
24.         '4':four,
25.         '5':five,
26.         '6':six,
27.         '7':seven,
28.         '8': eight,
29.         '9': nine,
30.         }
31.  
32.     for crate in stacks:
33.         if crate[:4] != '    ':
34.             one.append(crate[1])
35.         if crate[4:8] != '    ':
36.             two.append(crate[5])
37.         if crate[8:12] != '    ':
38.             three.append(crate[9])
39.         if crate[12:16] != '   ':
40.             four.append(crate[13])
41.         if crate[16:20] != '   ':
42.             five.append(crate[17])  
43.         if crate[12:16] != '   ':
44.             six.append(crate[21])  
45.         if crate[16:20] != '   ':
46.             seven.append(crate[25])
47.         if crate[20:24] != '   ':
48.             eight.append(crate[29])
49.         if crate[24:27] != '  ':
50.             nine.append(crate[33])    
51.        
52.     # Tidy up empty list elements
53.     for stack in stacks_dict.keys():
54.         stacks_dict[stack] = [crate for crate in stacks_dict[stack] if crate != ' ']
55.    
56.  
57.     # Follow instrcution to move crates across stacks
58.     for instruction in instructions:
59.         quanity, source, dest = re.findall(r'[0-9][0-9]*', instruction)
60.         move = stacks_dict[source][:int(quanity)]
61.         for x in move:
62.             stacks_dict[source].remove(x)
63.         stacks_dict[dest] = move + stacks_dict[dest]
64.          
65. # Concatente first element of list to find answer
66. answer = ''
67. for stack in stacks_dict.values():
68.     answer += stack[0]
69.  
70. print(answer)