库中对象实例的问题

Question

我正在尝试在我的库中创建config.py，因为在每个脚本中都包含以下代码：

config = ""
try:
    config = configparser.ConfigParser()
    if (configFile is None) or (configFile == ""):
        configReadArrayLength = len(config.read(pathABSofScript + 'config.ini'))
    else:
        configReadArrayLength = len(config.read(configFile))
    if configReadArrayLength == 0:
        print("Script could not find configuration file.")
        exit(1)
except Exception as ex:
    print("An exception of typ {0} occurred in config parsing function. Arguments:\n{1!r} exiting."
          .format(type(ex).__name__, ex.args))
    exit(1)

    def get_config_value(value):
try:
    return config['environment'][value]
except KeyError:
    return None
except Exception as config_value_exception:
    standard_logger_error(type(config_value_exception).__name__, config_value_exception.args)

我不想重复代码。因此，我遵循的步骤是：

0）结构如下：

/
scripts/
        somescript.py
        lib/
            config.py

1）在我的somescript.py中，我输入：

sys.path.insert(0, /home/user/some/path/lib')
import config

2）config.py内容：

import configparser


config = ""


def create_config_instance(path, file_name):
    try:
        global config
        config = configparser.ConfigParser()
        configReadArrayLength = len(config.read(path + file_name))
        if configReadArrayLength == 0:
            raise IOError("Cannot read config file")
    except Exception as ex:
        raise Exception("An exception of typ {0} occurred in config parsing function. Arguments:\n{1!r} exiting.".format(type(ex).__name__, ex.args))


def get_config_value(value):
    try:
        global config
        section = config['DEFAULT']['section_to_use']
        # return config[section][value]
        return "ELO"
    except KeyError:
        raise KeyError
    except Exception as config_value_exception:
        # return str(type(config_value_exception).__name__, config_value_exception.args)
        raise Exception(config_value_exception)

3）somescript.py的内容

#!/usr/bin/python3.6

import unittest
import os
import sys
import platform
sys.path.insert(0, '/scripts/lib')
import logger
import config


pathABSofScript = ""
if platform.system() == "Linux":
    pathABSofScript = str(os.path.realpath(__file__).rsplit('/', 1)[0]) + "/"
else:
    print("Unknown linux")
    exit(1)

# I'm creating instance of config.py object and passing there location of a file and file name
config_instance = config.create_config_instance(pathABSofScript, "config.ini")
# I'm trying to get value from config.ini
pathDBfile = config_instance.get_config_value("pathDBfile")
print(pathDBfile)

class TestDatabase(unittest.TestCase):

    def test_upper(self):
        self.assertEqual('foo'.upper(), 'FOO')


if __name__ == '__main__':
    unittest.main()

我正遇到此错误：

File "./somescript.py", line 21, in <module>
pathDBfile = config_instance.get_config_value("pathDBfile")
AttributeError: 'NoneType' object has no attribute 'get_config_value'

有人可以给我提示解决我的问题吗？