将file1的每一行复制到file2的其他每行中（Python）

Question

对不起，标题太荒谬了； 这可能就是为什么我无法在Google上找到答案的原因。

我有5个文本文件要合并为1。我想要这样的格式：

line1 of file1
line1 of file2
line1 of file3
line1 of file4
line1 of file5
line2 of file1
line2 of file2
line2 of file3
line2 of file4
line2 of file5

等等。

我尝试使用下面的bash命令，但对于sed或类似内容来说似乎太多了：它只是将文本插入到第一行，而不是我正在调用的变量的行。

for ((num=1; num<=66; num++)) ; do
    queryline=$(sed -n "${num}p" "file2.txt")
    sed -i "${num}i ${queryline}" "file1.txt"
done

（我也尝试过）

for ((num=1; num<=66; num++)) ; do
    numa=$((num + 1))
    queryline=$(sed -n "${num}p" "file2.txt")
    sed -i "${numa}i ${queryline}" "file1.txt"
done

我认为使用python（3.4）可能会更容易，但是我不确定如何做到这一点。 提示请任何人？

Answer 1

使用contextlib.ExitStack（）将输入文件作为一个组来处理，并使用zip来读取所有文件中的行：

import contextlib
import os

filenames = ['a','b','c','d','e']
output_file = 'fred'

# setup files for test
for filename in filenames:
    with open(filename, 'w') as fp:
        for i in range(10):
            fp.write('%s %d\n' % (filename, i))
if os.path.exists('fred'):
    os.remove('fred')

# open all the files and use zip to interleave the lines    
with open(output_file, 'w') as out_file, contextlib.ExitStack() as in_files:
    files = [in_files.enter_context(open(fname)) for fname in filenames]
    for lines in zip(*files):
        # if you're not sure last line has a \n
        for line in lines:
            out_file.write(line)
            if not line.endswith('\n'):
                out_file.write('\n')
        # if you are sure last line has a \n
        # out_file.write(''.join(lines))

print(open('fred').read())

Answer 2

如果确定只有5个文件，则可以使用。 如果您需要在不同数量的文件上执行此操作，它将变得更加复杂。

with open("file1.txt") as f:
    file1 = f.readlines()
with open("file2.txt") as f:
    file2 = f.readlines()
with open("file3.txt") as f:
    file3 = f.readlines()
with open("file4.txt") as f:
    file4 = f.readlines()
with open("file5.txt") as f:
    file5 = f.readlines()
outfile = open("outfile.txt", "w")
for aline in [line for foo in zip(file1, file2, file3, file4, file5) for line in foo]:
    outfile.write(aline)
outfile.close()

Answer 3

您的bash无效，因为您尝试插入的行在插入之前不存在。

echo "\n" > file_to_insert.txt
for i in {1..5};do
  for((num=1;num<66;num++);do
    line_num=$((num*i)
    queryline=$(sed -n '${num}p' 'file${i}.txt'
    sed -i "${num}i '$queryline'" 'file_to_insert.txt'
done

Answer 4

这是一个gnu awk （对ARGIND （文件选择器）执行gnu do）

awk -v t=5 '{c=c<FNR?FNR:c; for (i=1;i<=t;i++) if (ARGIND==i) a[i FS FNR]=$0} END {for (i=1;i<=c;i++) for (j=1;j<=t;j++) print a[j FS i]}' file1 file2 file3 file4 file5

您将t设置为文件数。

例：

cat f1
file1 one
file1 two
file1 three
file1 four

cat f2
file2 one
file2 two
file2 three
file2 four

cat f3
file3 one
file3 two
file3 three
file3 four

awk -v t=3 '{c=c<FNR?FNR:c; for (i=1;i<=t;i++) if (ARGIND==i) a[i FS FNR]=$0} END {for (i=1;i<=c;i++) for (j=1;j<=t;j++) print a[j FS i]}' f1 f2 f3
file1 one
file2 one
file3 one
file1 two
file2 two
file3 two
file1 three
file2 three
file3 three
file1 four
file2 four
file3 four

---

它是如何工作的？

awk -v t=3 '                    # Set t to number of files
    {c=c<FNR?FNR:c              # Find the file with most records and store number in c
    for (i=1;i<=t;i++)      # Loop trough one and one file
        if (ARGIND==i)          # Test what file we are on
            a[i FS FNR]=$0}     # Stor data in array a
END {
    for (i=1;i<=c;i++)          # Loop trough line number
        for (j=1;j<=t;j++)      # Loop trough file number
            print a[j FS i]}    # Print data from array
' f1 f2 f3                      # Read the files

Answer 5

要实现您想要的目标，一个很好的可能性就是坚持使用标准实用程序：在这里建议paste （由POSIX指定）：

paste -d '\n' file1 file2 file3 file4 file5

或者，如果您喜欢Bashisms：

paste -d '\n' file{1..5}

这可以简单地推广到任意数量的文件。