运行py文件时报错， TypeError: cannot concatenate 'str' and 'NoneType' objects
问题相关代码
```def load_env_variable(variable, default, variable_type=int):
"""
Loading environmental variables
:param variable: name of the variable
:param default: default value if the environmental variable is not defined within .env
:param variable_type: form that the variable should take
:return:
"""
if variable in os.environ:
if variable_type is int:
return int(os.environ[variable])
elif variable_type is float:
return float(os.environ[variable])
elif variable_type is str:
return str(os.environ[variable])
elif variable_type is bool:
return bool(int(os.environ[variable]))
else:
return default
SUBMISSION = load_env_variable("SUBMISSION", default=None, variable_type=str)
os.system('echo "run="' + SUBMISSION)
运行结果及报错内容
Traceback (most recent call last):
File "./settings.py", line 31, in <module>
os.system('echo "run="' + SUBMISSION)
TypeError: cannot concatenate 'str' and 'NoneType' objects
