I wish to dynamically import a module in Python (3.7), whereby the module's code is defined within a string.
Below is a working example that uses the imp
module, which is deprecated in favour of importlib
(as of version 3.4):
import imp
def import_code(code, name):
# create blank module
module = imp.new_module(name)
# populate the module with code
exec(code, module.__dict__)
return module
code = """
def testFunc():
print('spam!')
"""
m = import_code(code, 'test')
m.testFunc()
Python's documentation states that importlib.util.module_from_spec()
should be used instead of imp.new_module()
. However, there doesn't seem to be a way to create a blank module object using the importlib
module, like I could with imp
.
How can I use importlib
instead of imp
to achieve the same result?
You can simply instantiate types.Module
:
import types
mod = types.ModuleType("mod")
Then you can populate it with exec
just like you did:
exec(code, mod.__dict__)
mod.testFunc() # will print 'spam!'
So your code will look like this:
import types
def import_code(code, name):
# create blank module
module = types.ModuleType(name)
# populate the module with code
exec(code, module.__dict__)
return module
code = """
def testFunc():
print('spam!')
"""
m = import_code(code, 'test')
m.testFunc()
As commented by @Error - Syntactical Remorse, you should keep in mind that exec
basically executes whatever code is contained in the string you give it, so you should use it with extra care.
At least check what you're given, but it'd be good to use exclusively predefined strings.