Python – How to Import * from Module Name from Variable

pythonpython-import

As discussed here, we can dynamically import a module using string variable.

import importlib
importlib.import_module('os.path')

My question is how to import * from string variable?

Some thing like this not working for now

importlib.import_module('os.path.*')

Best Answer

You can do the following trick:

>>> import importlib
>>> globals().update(importlib.import_module('math').__dict__) 
>>> sin
<built-in function sin>

Be warned that makes all names in the module available locally, so it is slightly different than * because it doesn't start with __all__ so for e.g. it will also override __name__, __package__, __loader__, __doc__.

Update:

Here is a more precise and safer version as @mata pointed out in comments:

module = importlib.import_module('math')

globals().update(
    {n: getattr(module, n) for n in module.__all__} if hasattr(module, '__all__') 
    else 
    {k: v for (k, v) in module.__dict__.items() if not k.startswith('_')
})

Special thanks to Nam G VU for helping to make the answer more complete.

Related Solutions

Python – How to Dynamically Import a Module by Full Path

Let's have MyClass in module.name module defined at /path/to/file.py. Below is how we import MyClass from this module

For Python 3.5+ use (docs):

import importlib.util
import sys
spec = importlib.util.spec_from_file_location("module.name", "/path/to/file.py")
foo = importlib.util.module_from_spec(spec)
sys.modules["module.name"] = foo
spec.loader.exec_module(foo)
foo.MyClass()

For Python 3.3 and 3.4 use:

from importlib.machinery import SourceFileLoader

foo = SourceFileLoader("module.name", "/path/to/file.py").load_module()
foo.MyClass()

(Although this has been deprecated in Python 3.4.)

For Python 2 use:

import imp

foo = imp.load_source('module.name', '/path/to/file.py')
foo.MyClass()

There are equivalent convenience functions for compiled Python files and DLLs.

Python Dynamic Module Import – How to Import a Module by Name

With Python older than 2.7/3.1, that's pretty much how you do it.

For newer versions, see importlib.import_module for Python 2 and Python 3.

Or using __import__ you can import a list of modules by doing this:

>>> moduleNames = ['sys', 'os', 're', 'unittest'] 
>>> moduleNames
['sys', 'os', 're', 'unittest']
>>> modules = map(__import__, moduleNames)

Ripped straight from Dive Into Python.

Best Answer

Related Solutions

Python – How to Dynamically Import a Module by Full Path

Python Dynamic Module Import – How to Import a Module by Name

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