运行Python代码：subprocess.check_output（），出现错误：[Winerror 2]

Question

I'm running some Python code that is meant to run an Apache Maven program on a file and produce an output:

import os, subprocess
os.chdir("C:/Users/Mohammad/Google Drive/PhD/Spyder workspace/production-consumption/logtool-examples/")
logtoolDir = "C:/Users/Mohammad/Google Drive/PhD/Spyder workspace/production-consumption/logtool-examples/"
processEnv = {'JAVA_HOME': 'C:/Program Files/Java/jdk1.8.0_66/jre',
          'mvn': 'C:/Program Files/apache-maven-3.3.3/bin/'}
#processEnv = "C:/Program Files/Java/jdk1.8.0_66"
args = 'org.powertac.logtool.example.ProductionConsumption D:/PowerTAC/Logs/2015/log/powertac-sim-1.state testrunoutput.data'
subprocess.check_output(['mvn', ' exec:exec',
                             ' -Dexec.args=' + args],
                             env = processEnv,
                             cwd = logtoolDir)

However, it gives me this error:

File "C:/Users/Mohammad/Google Drive/PhD/Spyder workspace/production-consumption/test.py", line 25, in <module>
cwd = logtoolDir)

File "C:\WinPython-64bit-3.4.3.6\python-3.4.3.amd64\lib\subprocess.py", line 607, in check_output
with Popen(*popenargs, stdout=PIPE, **kwargs) as process:

File "C:\WinPython-64bit-3.4.3.6\python-3.4.3.amd64\lib\subprocess.py", line 859, in __init__
restore_signals, start_new_session)

File "C:\WinPython-64bit-3.4.3.6\python-3.4.3.amd64\lib\subprocess.py", line 1112, in _execute_child
startupinfo)

FileNotFoundError: [WinError 2] The system cannot find the file specified

I've investigated some things and I've narrowed it down to what I'm expecting is _winapi.CreateProcess being unable to find the Apache Maven installation (and run the mvn command). The installation is already in my path env variables (the line runs just fine through CMD). It may also be true that I've somehow defined the directories wrongly, but I fail to find a problem there... Can anyone offer a suggestion on how to fix this issue?

Cheers.

Answer 1

You can try appending "shell = True" to the arguments passed to subprocess like so:

subprocess.check_output(['mvn', ' exec:exec',
                         ' -Dexec.args=' + args],
                         env = processEnv,
                         cwd = logtoolDir, shell = True)

Though as it says here , this can be a security risk if the contents of the call can be determined by an external source, but I can't tell whether that's the case from the code you've given.