What’s happening under the hood? When Python detects a lazy import—typically triggered with the lazy keyword on the import line, as shown above—it doesn’t perform the usual import process. Instead, it creates a “proxy object,” or a stand-in, for the imported module. That proxy waits until the program tries to do something with the module. Then the actual import action triggers, and the module is evaluated.
The lazy keyword is always the first word on the line of an import you want to declare as lazy:
# lazily imports foo
lazy import foo
# lazily imports bar from foo
lazy from foo import bar
# same with the use of "as":
lazy import foo as foo1
lazy from foo import bar as bar1
Where to use lazy imports in Python
The most common scenario for using lazy imports is to replace the usual workaround for avoiding a costly import at program startup. As I mentioned previously, placing the import inside a function, instead of at the top level of a module, causes the import to happen only when the function runs. But it also means the import is limited to the function’s scope, and is therefore unavailable to the rest of the module unless you apply another workaround.
