使子进程在Windows上找到git可执行文件

Question

import subprocess

proc = subprocess.Popen('git status')
print 'result: ', proc.communicate()

我在我的系统路径中有git,但是当我像这样运行子进程时,我得到:
WindowsError: [Error 2] The system cannot find the file specified

如何让子进程在系统路径中找到git？

Windows XP上的Python 2.6.

Answer 1

你在这里看到的问题是,由引擎下的子进程使用的Windows API函数CreateProcess不会自动解析其他可执行扩展.exe.在Windows上,'git'命令确实安装为git.cmd.因此,您应该修改示例以显式调用git.cmd:

import subprocess

proc = subprocess.Popen('git.cmd status')
print 'result: ', proc.communicate()

这个原因git适用shell==True于Windows shell自动解析git的时候git.cmd.

最后,自己解决git.cmd:

import subprocess
import os.path

def resolve_path(executable):
    if os.path.sep in executable:
        raise ValueError("Invalid filename: %s" % executable)

    path = os.environ.get("PATH", "").split(os.pathsep)
    # PATHEXT tells us which extensions an executable may have
    path_exts = os.environ.get("PATHEXT", ".exe;.bat;.cmd").split(";")
    has_ext = os.path.splitext(executable)[1] in path_exts
    if not has_ext:
        exts = path_exts
    else:
        # Don't try to append any extensions
        exts = [""]

    for d in path:
        try:
            for ext in exts:
                exepath = os.path.join(d, executable + ext)
                if os.access(exepath, os.X_OK):
                    return exepath
        except OSError:
            pass

    return None

git = resolve_path("git")
proc = subprocess.Popen('{0} status'.format(git))
print 'result: ', proc.communicate()