lazimp 0.0.4

Lazy import of packages and modules

LazImp

LazImp is a package that allows lazy loading of python modules, packages and symboles for python 3.10+. This package allows you to load modules and packages only when the user use it. From dynamic import to "I only need this function, not the whole framework", the start-up time is speed-up and delayed over the execution of the software.

Example

First, you may have long loading or memory heavy modules to expose in your package api:

# package/heavy_module.py
print('Heavy module is loading...')
from time import sleep

sleep(10)
print('heavy_module loaded')

But instead of importing them directly, you can do a lazy import in the __init__.py:

# package/__init__.py of a package
import lazimp

math: lazimp.ModuleType
heavy_module: lazimp.ModuleType

__getattr__ = lazimp.lazy_import(
    'math',
    heavy_module='package',
)

Now, when you import the package:

# main.py
import package

print('Before access to heavy_module')
print(package.heavy_module)
print('After access to heavy_module')
print('Before access to math')
print(package.math)
print('After access to math')

And the output:

Before access to heavy_module
Heavy module is loading...
(wait 10 sec)
heavy_module loaded
<module 'heavy_module' from '...'>
After access to heavy_module
Before access to math
<module 'math' (built-in)>
After access to math

Without the lazy loading of heavy_module.py, the output would have been:

Heavy module is loading...
(wait 10 sec)
heavy_module loaded
Before access to heavy_module
<module 'heavy_module' from '...'>
After access to heavy_module