int.from_bytes() Bytes to int
Last updated: 2026-09-22
int.from_bytes() Bytes to int
int.from_bytes(bytes, byteorder) converts bytes to an int using the given byte order.
| Category | Number Methods |
|---|---|
| Kind | Built-in Type Method |
| Python Version | all |
📝 Syntax
int.from_bytes()⚙️ Parameters
| bytes Required | The bytes or bytearray to convert. |
|---|---|
| byteorder Required | Byte order: 'big' for most-significant first, 'little' for least-significant first. |
| signed Optional | Whether to interpret the result as signed two's complement.（Default：False） |
Returns：int. The integer decoded from bytes with the given byte order.
Mutates the original：No (returns a new object)
💥 Raises
ValueError— Raised when byteorder is invalid.TypeError— Raised when bytes is not a bytes-like object.
▶ Example
Edit the code, press Run, and see the result in the output panel:
Output：
255
255💡 Related Cases
More case studies coming soon — check back later.
❓ FAQ
QIs from_bytes() a class method?
AYes; call it directly as int.from_bytes(b, 'big'), no instance needed.
QWhat are the parameters?
AThe required bytes (bytes or bytearray) and byteorder ('big'/'little'); with signed=True it decodes by two's complement into a negative number.
QWhat is its relationship to to_bytes()?
AThey are inverse operations: as long as there is no overflow, int.from_bytes(x.to_bytes(2, 'big'), 'big') equals x.
QHow do I parse network byte order data?
ANetwork protocols mostly use big-endian: int.from_bytes(data, 'big').
