Python：传递给子进程一个临时生成的文件，而不是作为最后一个参数

Question

how to use subprocess if my temp-file argument is in the middle of the command? For example a terminal command looks like this:

program subprogram -a -b tmpFILE otherFILE

I tried variations of this:

from subprocess import Popen, PIPE
from tempfile import SpooledTemporaryFile as tempfile
tmpFILE=tempfile()
tmpFILE.write(someList)
tmpFILE.seek(0)
print Popen(['program','subprogram', '-a', '-b', otherFile],stdout=PIPE,stdin=tmpFILE).stdout.read()
f.close()

or

print Popen(['program','subprogram', '-a', '-b', tmpFILE, otherFile],stdout=PIPE,stdin=tmpFILE).stdout.read()

but nothing works... My temporary generated file in python shouldn't be as the last parameter.

Thanks

Answer 1

Is there a reason to use SpooledTemporaryFile instead of other types of temp file? If not, I recommend using NamedTemporaryFile as you can retrieve the name from it. I have tried to retrieve the name from SpooledTemporaryFile and got '<fdopen>' which does not seem to be valid.

Here is the suggested code:

from subprocess import Popen, PIPE
import tempfile

with tempfile.NamedTemporaryFile() as temp_file:
    temp_file.write(someList)
    temp_file.flush()
    process = Popen(['program', 'subprogram', '-a', '-b', temp_file.name, otherFile], stdout=PIPE, stderr=PIPE)
    stdout, stderr = process.communicate()

Discussion

• Using the with statement, you don't have to worry about closing the file. As soon as the with block is finished, the file is automatically closed.
• Instead of calling seek , you should call flush to commit your file buffer to disk before calling program .