how should I change "__main__" str to run file that has if __name__=="__main_

I have many python files and sometimes I need to check them if they works. So they require different import ways in the file for libraries. The below code explains the situation.

I use else situations for fles that import XLS.

XLS.py

if __name__ == "__main__":
    import config
else:
    import DataLoaders.config as config

However I want to add dataset.py file to if situation.

if __name__ == "__main__" or __name__=="dataset.py":
    import config
else:
    import DataLoaders.config as config

I tried above code but it doesn't work. How to add the file name in if to import config file as demanded?

CodePudding user response：

Frequently this is better accomplished by either (though logically these end up the same because they both split import logic off)

splitting off functionality into separate files and importing it where needed
keeping all of the relevant logic together in a custom class or method of one

An example of this using @classmethod (which largely exists to aid this sort of design) could be

class MyClass:

    @classmethod
    def from_XLS(cls, xls_path):
        import custom_xls_loader
        data = custom_xls_loader.load(xls_path)
        # call any other other needed transform methods
        # opportunity to make result an instance of this class
        #   (otherwise why not use a normal function)
        return cls(data)

This is used for optional support in many large libraries (where there may be a huge number of busy dependencies that a user may not want or need to install for their use case)
Here's an example from Pandas where some Apache Arrow support is optional https://github.com/pandas-dev/pandas/blob/bbb1cdf13a1e9240b43d691aa0ec3ca1b37afee4/pandas/core/arrays/arrow/dtype.py#L112

Or in your case (referring to config as self.config in the class or as the .config property of an instance)

class MyClass

    def __init__(self, data, config=None)
        if config is None:
            import config
        self.config = config

    @classmethod
    def from_config_normal(cls, data):
        return cls(data)

    @classmethod
    def from_DataLoaders_config(cls, data):
        import DataLoaders.config as config
        return cls(data, config)

CodePudding user response：

__name__ is set to the name of the module, not whatever creates the module. So in XLS.py, its value is either "__main__", if the file is executed as a script, or XLS, if the module is imported by someone else.

The problem here is that config is, to some extent, a parameter for your module, whose value is determined elsewhere. (config, if you execute as a script, Databases.config if you import from dataset.py, maybe some other module if you import from elsewhere.)

Python, unfortunately, doesn't allow you to parameterize an import like you can a function. A workaround is to simply leave config undefined in XLS.py, and leave the caller the responsibility to set the value appropriately.

# XLS.py
...

if __name__ == "__main__":
   import config
   ...

# dataset.py
import XLS
import DataLoaders

XLS.config = DataLoaders.config
...

This works as long as XLS doesn't use config at import time; I assume it's just a name that other functions in the module may refer to when they are called.

CodePudding user response：

__file__ return the path of the python file that is currently running. You can use the fonction os.path.basename() to extract only the name of the file.

Here is an example:

import os

filename = os.path.basename(__file__)
print(filename)

It returns:

>>> test.py

You can then use a condition to check the name of the file and import the desired modules.