Bytes ​

The type used to represent sequences of bytes in SmartPy is sp.TBytes.
The corresponding type in Michelson is

Michelson bytes

See reference Strings and Bytes template.

Literals ​

sp.bytes(<byte_sequence_string>)
Create a literal of type sp.TBytes in hexadecimal notation.

Examples ​

sp.bytes("0x0dae11")

Operations ​

Concatenation ​

expr1 + expr2
Concatenate two sequences of sp.TBytes.

Example ​

result = sp.bytes("0x0dae11") + sp.bytes("0x0dae11")

sp.concat(<l>)
Concatenate a list l of sp.TBytes.

Example ​

result = sp.concat([sp.bytes("0x0dae11"), sp.bytes("0x0dae11")])

Michelson CONCAT

Obtaining Size ​

sp.len(<expression>)
Return the length of <expression>.

Example ​

size = sp.len(sp.bytes("0x0dae11"))

Michelson SIZE

Slicing ​

sp.slice(<expression>, offset=<offset>, length=<length>)
Slice expression of type sp.TBytes from offset for length characters.

It returns an expression of type sp.TOption(sp.TBytes).

Example ​

sp.slice(sp.bytes("0x0dae11"), 1, 2) # 0xae11

Michelson SLICE

Other operations ​

Packing and Unpacking Data ​

sp.pack and sp.unpack are used for serializing/deserializing pieces of data. It heavily relies on sp.TBytes type.

Hashing Functions ​

sp.blake2b, sp.sha256, sp.sha512, sp.sha3, sp.keccak expect a single argument of type sp.TBytes representing the content to be hashed and return the result as sp.TBytes.

Hashing functions are documented here.

Utils ​

Conversion from string to bytes ​

sp.utils.bytes_of_string(<string>)
Encode a constant string to sp.TBytes.

Example ​

result = sp.utils.bytes_of_string("A String")