A closure is a special function that can access variables defined in the scope of its outer function. In other words, a closure can remember and access the context in which it was created. In Python, closures can be implemented by defining a function that returns another function. This makes closures a very useful programming tool because it helps us write cleaner, more modular code. This article will introduce Python closures and their usage in detail, and provide some examples to illustrate their concepts and applications.
Basic concepts of closure
In Python, a closure consists of an inner function and a reference to its surrounding state (i.e., non-local variables). An inner function can "capture" variables from an outer function when it is created and maintain access to those variables throughout its lifetime. This design allows the inner function to access both its own local variables and the variables of the outer function.
The basic structure of a closure is as follows:
def outer_function(parameter):
# 在外部函数内定义内部函数
def inner_function():