Where in memory does Python store variable definitions?

In Python, variable definitions are stored in namespaces, which are implemented as dictionaries (dict). Depending on the scope, a variable is stored in one of three main namespaces:

• Local namespace of a function or method — variables defined inside the function are stored in the local dictionary.
• Module's global namespace — variables defined at the module level are stored in the module's dictionary.
• Built-in namespace (builtins) — contains Python's built-in names.

When accessing a variable, Python first looks in the local namespace, then in the global namespace, and finally in the built-in namespace.

Example:

x = 10  # global variable

def func():
    y = 5  # local variable
    print(x, y)

func()  # Output: 10 5

Thus, variable definitions are stored in the corresponding namespace dictionaries in memory, and the objects themselves are stored in the heap.