为什么 Python 不使用工作目录以及如何修复它？

Question

我有一个问题，需要很长时间才能解释，所以我将把它分解成有趣的部分。我尝试使用 kconfiglib.py 解析一些 kconfig。这是我的代码（config.in）

[intro_code]
source "b.in"

我的代码完全按照 [intro_code] 的方式进行。我不确定source 是否是python 关键字，但它是关于输入/包含不同的文件（这里名称为b.in，与执行的脚本位于同一文件夹中）

错误信息：现在运行脚本时，出现以下错误信息：

IOError: config.in:51: sourced file "b.in" (expands to
"b.in") not found. Perhaps base_dir
(argument to Config.__init__(), currently
"$srctree") is set to the wrong value.

我做了什么来解决：我试图将工作目录更改为Sourcecodes（这是config.in 和b.in 所在的位置）在config.in 之上：

os.chdir("/home/fedor/Sourcecodes") 
retval = os.getcwd()
print "Directory changed successfully %s" % retval

在执行期间它返回：

目录更改成功 /home/fedor/Sourcecodes

所以目录似乎没问题，但仍然出现相同的错误消息。

它在什么时候起作用：使用b.in 的绝对路径（如source "/home/fedor/Sourcecodes/b.in") 然后它起作用了，但这不是我可以使用脚本的方式。

有谁知道如何告诉 python 与执行的脚本在同一目录中查找？

[编辑：]如愿，完整代码：

我打电话给python /home/fedor/Sourcecodes/Kconfiglib/examples/print_tree.py /home/fedor/Sourcecodes/config.in

来自 kconfiglib-examples 的 print_tree.py：

# Prints a tree of all items in the configuration

import kconfiglib
import sys
import os

os.chdir("/home/fedor/BR1311") 


retval = os.getcwd()

print "Directory changed successfully %s" % retval

def print_with_indent(s, indent):
    print (" " * indent) + s

def print_items(items, indent):
    for item in items:
        if item.is_symbol():
            print_with_indent("config {0}".format(item.get_name()), indent)
        elif item.is_menu():
            print_with_indent('menu "{0}"'.format(item.get_title()), indent)
            print_items(item.get_items(), indent + 2)
        elif item.is_choice():
            print_with_indent('choice', indent)
            print_items(item.get_items(), indent + 2)
        elif item.is_comment():
            print_with_indent('comment "{0}"'.format(item.get_text()), indent)

conf = kconfiglib.Config(sys.argv[1])
print_items(conf.get_top_level_items(), 0)

---

config.in

menu "Audio and video applications"
config BR2_PACKAGE_WIPE
    bool "wipe"
    help
      Wipe is a little command for securely erasing files
      from magnetic media. It compiles under various unix platforms.

      http://wipe.sourceforge.net

config BR2_PACKAGE_BONNIE
    bool "bonnie++"
    depends on BR2_INSTALL_LIBSTDCPP
    depends on BR2_USE_MMU # fork()
    help
      Filesystem tester

      http://www.coker.com.au/bonnie++/

comment "bonnie++ needs a toolchain w/ C++"
    depends on BR2_USE_MMU
    depends on !BR2_INSTALL_LIBSTDCPP
endmenu

source "b.in"

---

和b.in（与config.in完全相同，但最后缺少source命令）：

menu "Audio and video applications"
config BR2_PACKAGE_WIPE
    bool "wipe"
    help
      Wipe is a little command for securely erasing files
      from magnetic media. It compiles under various unix platforms.

      http://wipe.sourceforge.net

config BR2_PACKAGE_BONNIE
    bool "bonnie++"
    depends on BR2_INSTALL_LIBSTDCPP
    depends on BR2_USE_MMU # fork()
    help
      Filesystem tester

      http://www.coker.com.au/bonnie++/

comment "bonnie++ needs a toolchain w/ C++"
    depends on BR2_USE_MMU
    depends on !BR2_INSTALL_LIBSTDCPP
endmenu

Answer 1

答案就在您发布的错误消息中：

Perhaps base_dir (argument to Config.__init__(), currently "$srctree") 
is set to the wrong value.

查看 github 上的 source，Config 类的 __init__ 接受多个参数，所有参数都具有默认值。

def __init__(self,
             filename = "Kconfig",
             base_dir = "$srctree",
             print_warnings = True,
             print_undef_assign = False):

...在该类的文档字符串中，解释了base_dir 参数：

base_dir (default: "$srctree") -- The base directory relative to which
'source' statements within Kconfig files will work. For the
Linux kernel this should be the top-level directory of the
kernel tree. $-references to environment variables will be
expanded.

The environment variable 'srctree' is set by the Linux makefiles
to the top-level kernel directory. A default of "." would not
work if an alternative build directory is used.

我怀疑如果您将'/home/fedor/BR1311' 传递给这个__init__ 而不是更改为它，例如：

conf = kconfiglib.Config(sys.argv[1], '/home/fedor/BR1311')

事情会好很多。