What is SetValueEx in the winreg Python module?

winreg, or Windows registry access, provides functions that expose the Windows registry API to Python. Windows registry is a collection of databases that stores the information and settings of software programs, hardware devices, user preferences, and operating-system configurations.

Registry handle objects

winreg uses a handle object as the registry handle to ensure that the handles are closed correctly, even in cases where the programmer might forget to close them.

The handle object wraps a windows HKEY object and automatically closes it when the object is destroyed. It also supports comparison semantics, so two handle objects will compare true if both of them point to the same Windows underlying handle value.

SetValueEx method

SetValueEx stores data in the value field of the specified key.

Syntax

winreg.SetValueEx(key, value_name, reserved, type, value)

Parameters

• key is an already opened key or one of the predefined HKEY_ constants. HKEY constants correspond to various registry entries such as environment variable settings, the physical state of the computer, user preferences, network connections, etc. We must open this key with KEY_SET_VALUE access.

• value_name is the subkey in the form of a string with which the value is associated.

• reserved is a random value. By default, zero is passed to the API.

• type is an integer that specifies the type of data.

• value is a string that defines the new value.

Values greater than 2048 bytes are suggested to be stored in files with the filenames stored in the configuration registry.

Return value

This method raises an auditing event winreg.SetValueEx with the parameters key, value_name, reserved, type, and value. An audit event is raised when an OS system-level change is made to be reported to the system audit logger that runs as part of the kernel.