struct.calcsize()
struct.calcsize() is a Python function in the Struct Module category. Returns the size of the struct (and bytes needed) for the given format. The syntax is struct.calcsize(format). Parameters: format. Returns: Integer byte size. A typical example: struct.calcsize(">II") # 8 (two 4-byte ints)
struct.calcsize("hhl") # 8 (2+2+4). A close sibling is struct.pack(), which packs values into a bytes object according to a format string. A close sibling is struct.unpack(), which unpacks bytes into values according to a format string. A close sibling is struct.pack_into(), which packs values into a buffer (bytearray) at the given offset. A close sibling is struct.unpack_from(), which unpacks bytes from a buffer starting at offset. More about this category: Binary data packing — pack, unpack, calcsize, pack_into. For a broader walkthrough, read the Struct Module guide. Related Struct Module entries: struct.pack(), struct.unpack(), struct.pack_into(), struct.unpack_from(). This page is part of the free Python Reference documentation covering 978+ functions, methods, and modules with examples and parameter details.