django.git/django/utils/functional.py, branch main

Fixed #36810 -- Avoided infinite recursion in SimpleLazyObject.repr().

2025-12-24T17:46:41Z

Detect when `SimpleLazyObject._setupfunc` is a bound method of the same instance to use a safe representation and avoid infinite recursion.

Refs #28909 -- Simplified code using unpacking generalizations.

2025-04-01T01:43:13Z

Allowed custom formatting of lazy() objects.

2023-06-12T04:09:20Z

This allows for formatting of lazy objects which have a custom formatter defined by overriding the default implementation from `object`.

Allowed multiplication of lazy() objects with int return type.

2023-06-12T03:59:40Z

Removed function call overhead when preparing proxy class for lazy().

2023-06-12T03:53:30Z

We can avoid the function call and assignment overhead which could be significant when instantiating many lazy objects. It's still easy enough to read too.

Made proxy class in lazy() prepare eagerly.

2023-06-12T03:45:44Z

Previously, the proxy class was prepared lazily: lazy_identity = lazy(identity, int) lazy_identity(10) # prepared here lazy_identity(10) This has a slight advantage that if the lazy doesn't end up getting used, the preparation work is skipped, however that's not very likely. Besides this laziness, it is also inconsistent in that the methods which are wrapped directly (__str__ etc.) are prepared already when __proxy__ is defined, and there is a weird half-initialized state. This change it so that everything is prepared already on the first line of the example above.

Improved order of methods in proxy class in lazy().

2023-06-12T03:33:02Z

This order reads more naturally and puts methods into three groups: 1. The methods required to support the implementation of __proxy__, e.g. __deepcopy__ doesn't come from `object` and __reduce__ is overridden to support behavior required explicitly for pickling of lazy objects. 2. Methods that are specifically overridden from `object` which we don't want to inherit from the provided resultclasses. These will be skipped later when we add methods from the resultclasses. 3. Additional methods - that is _add__, __radd__, and __mod__ - don't come from `object`, but typically from `str` and `int` which are the most common use cases. Co-authored-by: Nick Pope

Optimized lazy() by removing use of @total_ordering.

2023-06-08T07:17:50Z

@total_ordering is slow. Using the following micro-benchmark (resultclasses intentionally omitted to narrow the scope): import cProfile from django.utils.functional import lazy def identity(x): return x cProfile.run("for i in range(10000): str(lazy(identity)(1))") Before: 380003 function calls in 0.304 seconds ncalls tottime percall cumtime percall filename:lineno(function) 1 0.016 0.016 0.304 0.304 :1() 10000 0.002 0.000 0.002 0.000 bench.py:5(double) 10000 0.005 0.000 0.006 0.000 functional.py:100(__cast) 10000 0.007 0.000 0.013 0.000 functional.py:106(__str__) 10000 0.005 0.000 0.017 0.000 functional.py:140(__wrapper__) 10000 0.020 0.000 0.258 0.000 functional.py:60(lazy) 10000 0.039 0.000 0.039 0.000 functional.py:68(__proxy__) 10000 0.010 0.000 0.012 0.000 functional.py:77(__init__) 10000 0.002 0.000 0.002 0.000 functional.py:84(__prepare_class__) 10000 0.025 0.000 0.075 0.000 functools.py:186(total_ordering) 10000 0.015 0.000 0.028 0.000 functools.py:189() 10000 0.024 0.000 0.044 0.000 functools.py:37(update_wrapper) 10000 0.005 0.000 0.005 0.000 functools.py:67(wraps) 10000 0.074 0.000 0.114 0.000 {built-in method builtins.__build_class__} 1 0.000 0.000 0.304 0.304 {built-in method builtins.exec} 150000 0.023 0.000 0.023 0.000 {built-in method builtins.getattr} 10000 0.004 0.000 0.004 0.000 {built-in method builtins.max} 80000 0.025 0.000 0.025 0.000 {built-in method builtins.setattr} 1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects} 10000 0.003 0.000 0.003 0.000 {method 'update' of 'dict' objects} After: 240003 function calls in 0.231 seconds ncalls tottime percall cumtime percall filename:lineno(function) 1 0.016 0.016 0.231 0.231 :1() 10000 0.002 0.000 0.002 0.000 bench.py:5(double) 10000 0.006 0.000 0.012 0.000 functional.py:105(__str__) 10000 0.005 0.000 0.017 0.000 functional.py:159(__wrapper__) 10000 0.015 0.000 0.186 0.000 functional.py:60(lazy) 10000 0.022 0.000 0.022 0.000 functional.py:68(__proxy__) 10000 0.010 0.000 0.012 0.000 functional.py:76(__init__) 10000 0.002 0.000 0.002 0.000 functional.py:83(__prepare_class__) 10000 0.004 0.000 0.006 0.000 functional.py:99(__cast) 10000 0.023 0.000 0.043 0.000 functools.py:37(update_wrapper) 10000 0.004 0.000 0.004 0.000 functools.py:67(wraps) 10000 0.102 0.000 0.124 0.000 {built-in method builtins.__build_class__} 1 0.000 0.000 0.231 0.231 {built-in method builtins.exec} 70000 0.011 0.000 0.011 0.000 {built-in method builtins.getattr} 50000 0.007 0.000 0.007 0.000 {built-in method builtins.setattr} 1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects} 10000 0.003 0.000 0.003 0.000 {method 'update' of 'dict' objects}

Made bytes and str return types no longer mutually exclusive in lazy().

2023-06-08T07:15:40Z

They are no longer special cased.

Removed unnecessary wrapping of bytes in proxy class in lazy().