使用 Linux 命令的 Python 脚本不能在 Windows 上运行。有什么办法让它与操作系统无关吗？

Question

我有一个关于简单脚本的问题。该脚本的目标是找到子目录中的所有 tgz 文件，并从中提取文件名末尾带有 B4 或 B5 的所有 TIF 文件。之后，它将这些文件移动到指定的子目录(分别为 band4 或 band5)。

它似乎在我的 Ubuntu 12.04 机器上运行良好，但是当我的一个伙伴在他的 Windows 7 机器上执行它时，它就崩溃了。据我了解，脚本调用 linux 命令，Windows 无法正确解释它们(找不到 *.tgz 文件)。我想知道是否有办法让它与操作系统无关，从而达到相同的结果。

import subprocess, shlex, os, sys
cmd1 = "find . -name *.tgz" 
cmd2 = "xargs -i pigz -dv {}"
args1 = shlex.split(cmd1)
args2 = shlex.split(cmd2)

p1 = subprocess.Popen(args1, stdout=subprocess.PIPE)
p2 = subprocess.Popen(args2, stdin=p1.stdout, stdout=subprocess.PIPE)
p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
output = p2.communicate()[0]

cmd1 = "find . -name *.tar" 
cmd2 = "xargs -i tar -xfv {} --wildcards '*B5.TIF' '*B6.TIF' '*B8.TIF' -C %s" % repo 
args1 = shlex.split(cmd1)
args2 = shlex.split(cmd2)

p1 = subprocess.Popen(args1, stdout=subprocess.PIPE)
p2 = subprocess.Popen(args2, stdin=p1.stdout, stdout=subprocess.PIPE)
p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
output = p2.communicate()[0]

pathname = os.path.dirname(sys.argv[0])
b4 = os.path.abspath(pathname)+'/Band_4'
b5 = os.path.abspath(pathname)+'/Band_5'

os.mkdir(b4)
os.mkdir(b5)

cmd1 = "find . -name *B4.TIF" 
cmd2 = "xargs -i mv -if {} Band_4" 
args1 = shlex.split(cmd1)
args2 = shlex.split(cmd2)

p1 = subprocess.Popen(args1, stdout=subprocess.PIPE)
p2 = subprocess.Popen(args2, stdin=p1.stdout, stdout=subprocess.PIPE)
p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
output = p2.communicate()[0]

cmd1 = "find . -name *B5.TIF" 
cmd2 = "xargs -i mv -if {} Band_5" 
args1 = shlex.split(cmd1)
args2 = shlex.split(cmd2)

p1 = subprocess.Popen(args1, stdout=subprocess.PIPE)
p2 = subprocess.Popen(args2, stdin=p1.stdout, stdout=subprocess.PIPE)
p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
output = p2.communicate()[0]

错误回溯:

Traceback (most recent call last):
 File "[PATH]\bands.py", line 36, in <module>
   p2 = subprocess.Popen(args2, stdin=p1.stdout, stdout=subprocess.PIPE)
 File "C:\Python27\ArcGIS10.2\lib\subprocess.py", line 711, in _init_
   errread, errwrite)
 File "C:\Python27\ArcGIS10.2\lib\subprocess.py", line 948, in _execute_child
   startupinfo)
WindowsError: [Error 2] The system cannot find the file specified
File not found - *.tgz

Answer 1

应该不会太难，只要您了解脚本的作用以及使用的命令/实用程序的作用即可:

• find 可以替换为 os.walk 和 fnmatch.filter 的组合(参见 this answer 示例)
• xargs 需要替换为 Python for 循环，该循环在 os.walk
• pigz 可以替换为 Python gzip 模块
• tar 可以用tarfile库替换
• mv可以换成shutil.move

---

这是一个开始:

import errno
import fnmatch
import os
import re
import shutil
import tarfile


cwd = os.getcwd()
REPO = os.path.join(cwd, "repo")


def find(directory, pattern):
    for root, dirnames, filenames in os.walk(directory):
        for fn in filenames:
            if fnmatch.fnmatch(fn.lower(), pattern.lower()):
                yield os.path.join(root, fn)


def mkdir_p(path):
    try:
        os.makedirs(path)
    except OSError as exc:
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise


def mv(src, dst):
    try:
        shutil.move(src, dst)
    except shutil.Error, e:
        print "%s, moving on" % e


def matching_tif_files(members):
    pattern = re.compile(r'.*B[4568].tif', re.I)
    for tarinfo in members:
        if pattern.match(tarinfo.name):
            print "Extracting %s" % tarinfo.name
            yield tarinfo


targz_files = find(cwd, '*.tgz')

for tgz in targz_files:
    print tgz
    with tarfile.open(tgz) as tar:
        tar.extractall(path=REPO, members=matching_tif_files(tar))


b4 = os.path.join(cwd, 'Band_4')
b5 = os.path.join(cwd, 'Band_5')

mkdir_p(b4)
mkdir_p(b5)

b4_tifs = find(cwd, '*B4.tif')
for tif in b4_tifs:
    mv(tif, b4)

b5_tifs = find(cwd, '*B5.tif')
for tif in b5_tifs:
    mv(tif, b5)

脚本实际上做了一些与您描述的不同的事情。例如，--wildcards '*B5.TIF' '*B6.TIF' '*B8.TIF 与 *B4.TIF 不匹配。我按照我认为合适的方式改编了那些。它当然还不完美，但它应该可以帮助您入门。