我在这里要做的是从文件 DATA.txt 读取每行间隔 y 的 z 行，然后执行功能找到就行了。即我想跳过第一个 y 行;阅读下一个 z 行;在刚刚读入的那些行上执行 find 功能;跳过下一个 y 行;并重复文件的长度（传入 sys.argv [1] ）。
我在这里给了我一些变量行的空行，我不知道为什么。如果需要，我可以提供查找功能，但我认为这样更简单。
如果有人想要提出完全不同的做法，只要我了解正在发生的事情，我就会像修复现有代码一样快乐。
编辑：我错过了几个parens但添加它们并没有解决问题。import sys
import operator
import linecache
def find(arg)
...
x=0
while x<int(sys.argv[1]):
x+=1
if mod(x, y)==0:
for i in range(x,x+z):
block=linecache.getline('DATA.txt', i)
g = open('tmp','a+')
g.write(block)
linecache.clearcache()
lines=g.read()
find(lines)
g.close()
else:
pass
g.close()
f.close()
答案 0 :(得分：2)
编辑：尝试以下操作，我想我现在对您要做的事情有了更好的了解。
g = open('tmp','a+')
while x<int(sys.argv[1]):
x+=1
if mod(x, y)==0:
curr = g.tell()
for i in range(x,x+z):
block=linecache.getline('DATA.txt', i)
g.write(block)
linecache.clearcache()
g.seek(curr)
lines = g.read()
find(lines)
else:
pass
g.close()
答案 1 :(得分：1)
Maimon，您的初始代码与索引有关。安德鲁的代码也是错误的，因为他把你的代码作为一个开始。
查看安德鲁代码的结果，其中我删除了关于 g 的行：
import sys
import operator
import linecache
x=0
y=7 # to skip
z=3 # to print
#g = open('tmp','a+')
while x<23:
x+=1
print 'x==',x
if operator.mod(x, y)==0:
#curr = g.tell()
for i in range(x,x+z):
block=linecache.getline('poem.txt', i)
print 'block==',repr(block)
#g.write(block)
linecache.clearcache()
#g.seek(curr)
#lines = g.read()
#find(lines)
else:
pass
#g.close()
应用于名为'poem.txt'的文件，其中包含24行：
1 In such a night, when every louder wind
2 Is to its distant cavern safe confined;
3 And only gentle Zephyr fans his wings,
4 And lonely Philomel, still waking, sings;
5 Or from some tree, famed for the owl's delight,
6 She, hollowing clear, directs the wand'rer right:
7 In such a night, when passing clouds give place,
8 Or thinly veil the heav'ns' mysterious face;
9 When in some river, overhung with green,
10 The waving moon and trembling leaves are seen;
11 When freshened grass now bears itself upright,
12 And makes cool banks to pleasing rest invite,
13 Whence springs the woodbind, and the bramble-rose,
14 And where the sleepy cowslip sheltered grows;
15 Whilst now a paler hue the foxglove takes,
16 Yet checkers still with red the dusky brakes
17 When scattered glow-worms, but in twilight fine,
18 Shew trivial beauties watch their hour to shine;
19 Whilst Salisb'ry stands the test of every light,
20 In perfect charms, and perfect virtue bright:
21 When odors, which declined repelling day,
22 Through temp'rate air uninterrupted stray;
23 When darkened groves their softest shadows wear,
24 And falling waters we distinctly hear;
结果是：
x== 1
x== 2
x== 3
x== 4
x== 5
x== 6
x== 7
block== '7 In such a night, when passing clouds give place,\n'
block== "8 Or thinly veil the heav'ns' mysterious face;\n"
block== '9 When in some river, overhung with green,\n'
x== 8
x== 9
x== 10
x== 11
x== 12
x== 13
x== 14
block== '14 And where the sleepy cowslip sheltered grows;\n'
block== '15 Whilst now a paler hue the foxglove takes,\n'
block== '16 Yet checkers still with red the dusky brakes\n'
x== 15
x== 16
x== 17
x== 18
x== 19
x== 20
x== 21
block== '21 When odors, which declined repelling day,\n'
block== "22 Through temp'rate air uninterrupted stray;\n"
block== '23 When darkened groves their softest shadows wear,\n'
x== 22
x== 23
x== 24
x== 25
我选择y = 7作为要跳过的行数，但是第7行被打印出来。
此外，计数继续8,9,10 ...打印3行7-8-9（选择z = 3）而不是继续10,11,12 ...然后下一个印刷的3行是14-15-16，而它应该是7 + 3第一行之后的行，即11-12-13行
事实上，如果你想跳过7行，然后打印3行，打印的行必须是：
8-9-10
18-19-20
28-29-30
等
我是对的吗？
我的解决方案是：
def chunk_reading(filepath,y,z,x=0):
# x : number of lines to skip before the periodical treatment
# y : number of lines to periodically skip
# z : number of lines to periodically print
with open('poem.txt') as f:
try:
for sk in xrange(x):
f.next()
while True:
try:
for i in xrange(y):
print 'i==',i
f.next()
for j in xrange(z):
print 'j==',j
print repr(f.next())
except StopIteration:
break
except StopIteration:
print 'Not enough lines before the lines to print'
chunk_reading('poem.txt',7,3)
产生
i== 0
i== 1
i== 2
i== 3
i== 4
i== 5
i== 6
j== 0
"8 Or thinly veil the heav'ns' mysterious face;\n"
j== 1
'9 When in some river, overhung with green,\n'
j== 2
'10 The waving moon and trembling leaves are seen;\n'
i== 0
i== 1
i== 2
i== 3
i== 4
i== 5
i== 6
j== 0
'18 Shew trivial beauties watch their hour to shine;\n'
j== 1
"19 Whilst Salisb'ry stands the test of every light,\n"
j== 2
'20 In perfect charms, and perfect virtue bright:\n'
i== 0
i== 1
i== 2
i== 3
i== 4
上述解决方案甚至可用于无法记录在RAM中的大文件。
以下内容适用于尺寸有限的文件：
def slice_reading(filepath,y,z,x=0):
# x : number of lines to skip before the periodical treatment
# y : number of lines to periodically skip
# z : number of lines to periodically print
with open('poem.txt') as f:
lines = f.readlines()
lgth = len(lines)
if lgth > x+y:
for a in xrange(x+y,lgth,y+z):
print lines[a:a+z]
else:
print 'Not enough lines before lines to print'
slice_reading('poem.txt',7,3,5)
结果
['13 Whence springs the woodbind, and the bramble-rose,\n', '14 And where the sleepy cowslip sheltered grows;\n', '15 Whilst now a paler hue the foxglove takes,\n']
['23 When darkened groves their softest shadows wear,\n', '24 And falling waters we distinctly hear;']
答案 2 :(得分：0)
我认为您的问题可能就是lines=g.read行。它应该是lines=g.read()
答案 3 :(得分：0)
在“不同方法”类别中，我提供此（行号显然仅用于显示）：
1 """
2 Reading line lines from DATA.txt, first skip 3 lines, then print 2 lines,
3 then skip 3 more lines, etc.
4 """
5
6 def my_print(l):
7 if (my_print.skip_counter > 0):
8 my_print.skip_counter -= 1
9 else:
10 if (my_print.print_counter > 0):
11 my_print.print_counter -= 1
12 print l,
13 else:
14 my_print.skip_counter = my_print.skip_size
15 my_print.print_counter = my_print.print_size
16 my_print(l)
17
18 my_print.skip_size = 3
19 my_print.skip_counter = my_print.skip_size
20
21 my_print.print_size = 2
22 my_print.print_counter = my_print.print_size
23
24 data = open('DATA.txt')
25 for line in data:
26 my_print(line)
改进这个的第一种方法是用一个类包装my_print（）（用你的x和y作为成员变量）。如果你想要一些真正“pythonic”的东西，那么你可以充分利用发电机。