What data structure is used to organize a sequence of function or method calls?

In Python, a data structure called the call stack is used to organize the sequence of function or method calls.

When a function is called, information about the current state (return address, local variables, etc.) is placed on the call stack. After the function completes, this information is retrieved, and control returns to the call site.

This allows for nested calls, recursion, and tracking the execution order.

Example:

def foo():
    print('In foo')
    bar()

def bar():
    print('In bar')

foo()

When foo() is called, the context foo is placed on the stack, then when bar() is called, the context bar is added. After bar() finishes, control returns to foo, and then the program continues after the call to foo().