Getsize

Getsize is a function in Python’s standard library, specifically os.path.getsize, used to obtain the size of a filesystem path in bytes. It accepts a path-like object (such as a string, bytes, or a PathLike) and relies on the operating system’s stat information to determine the size.

The function follows symbolic links by default, returning the size of the target file. For regular files, the returned value is the file’s size in bytes. When the path refers to a directory, the value corresponds to the directory entry’s size as reported by the filesystem (the directory’s st_size), not the total size of its contents. Therefore, getsize is not suitable for calculating the combined size of a directory’s contents.

Usage considerations include error handling and input types. If the path does not exist or is inaccessible, os.path.getsize raises an OSError. If the provided path is of an unsupported type, a TypeError may be raised. The function uses the built-in fspath conversion, so it supports path-like objects in modern Python versions.

Related functionality includes using pathlib as an alternative interface (for example, Path('file').stat().st_size) and the broader os.stat family of functions for more detailed metadata. For cases where symlink behavior should be avoided, os.lstat can be used to obtain information about the link itself rather than the target.

In practical use, getsize is a quick way to retrieve a file’s size in bytes, useful in tasks such as validation, logging, or preparing data for transfer or storage.