Python:操纵列表

时间:2016-05-07 08:57:19

标签: python list python-3.x

问题

我必须从文本文件中获取元素,对角线,从顶部到按钮。它应该适用于letters.txt的任何维度。该文件看起来像这样:

文字档案:letters.txt(我认为这很难,我删除了' Y'以及' Z'来自我原来的帖子

A B C D E F
G H I J K L
M N O P Q R 
S T U V W X

列表应如下所示:

topButtom_List = ['AGMS', 'BHNT', 'CIOU', 'DJPV', 'EKQW', 'FLRX']

bLeftToURight = ['A', 'GB', 'MHC', 'SNID', 'TOJE', 'UPKF', 'VQL', 'WR', 'X']

我目前代码为top to buttom:

# top to buttom
topButtom_List = [] #should be ['AGMS', 'BHNT', 'CIOU', 'DJPV', 'EKQW', 'FLRX']

openFile = open("letters.txt")
for i in openFile:
    i = i.replace(" ","")
length = len(i)
openFile.close()

openFile = open("letters.txt")   
counter = 0   
for eachIterration in range(length):
    for line in openFile:
        line = line.replace(" ","")
        # counter should be added by 1 each time inner loop itterates x4, and outter loop x1.
        topButtom_List.append(line[counter]) 
    counter = counter + 1
openFile.close()

我尝试使用上述代码:

我试图从文本文件中获取顶部的buttom字符,并将其放入名为topButtom_List的列表中。我使用counter来定义索引,对于外循环所做的每次迭代,索引都会加1。我看到的方式是,外循环将启动,内循环将迭代x4,并在其中添加AGMS在第一次迭代时topButtom_List,外部循环将再次迭代并向计数器添加1。第二次迭代将添加BHNTZ,依此类推,外部循环将再次迭代并向计数器添加1。

从文本文件:letters.txt 我想填充topButtom_List

我得到的输出:

['A', 'G', 'M', 'S']

预期输出:

['AGMS', 'BHNT', 'CIOU', 'DJPV', 'EKQW', 'FLRX']

1 个答案:

答案 0 :(得分:1)

#!/usr/bin/python3

field = """A B C D E F
           G H I J K L
           M N O P Q R
           S T U V W X"""

arr = [col.split(' ') for col in [row.strip() for row in field.split('\n')]]
len_x, len_y = len(arr[0]), len(arr)
len_all = len_x + len_y - 1
lines, groups = [], []

for i in range(len_all):
    start = (i, 0) if i < len_y else (len_y-1, i-len_y+1)
    end = (0, i) if i < len_x else (i-len_x+1, len_x-1)
    lines.append([start, end])

print('List of start and end points: ', lines)

for start, end in lines:
    group = ''
    for i in range(len_x):
        y, x = start[0] - i, start[1] + i
        if y >= 0 and y < len(arr) and x < len(arr[y]):
            group += arr[y][x]
        else:
            groups.append(group)
            break

print(groups)

返回

List of start and end points:  [[(0, 0), (0, 0)], [(1, 0), (0, 1)],
[(2, 0), (0, 2)], [(3, 0), (0, 3)], [(3, 1), (0, 4)], [(3, 2), (0, 5)], 
[(3, 3), (1, 5)], [(3, 4), (2, 5)], [(3, 5), (3, 5)]]

['A', 'GB', 'MHC', 'SNID', 'TOJE', 'UPKF', 'VQL', 'WR', 'X']