puya:docs:lg-builtins.md•1.09 kB
# Python builtins
Some common python builtins have equivalent `algopy` versions, that use an [`UInt64`](#algopy.UInt64) instead of a native `int`.
## len
The `len()` builtin is not supported, instead `algopy` types that have a length have a `.length` property of type [`UInt64`](#algopy.UInt64). This is primarily
due to `len()` always returning `int` and the CPython implementation enforcing that it returns _exactly_ `int`.
## range
The `range()` builtin has an equivalent [`algopy.urange`](#algopy.urange) this behaves the same as the python builtin except that it returns
an iteration of [`UInt64`](#algopy.UInt64) values instead of `int`.
## enumerate
The `enumerate()` builtin has an equivalent [`algopy.uenumerate`](#algopy.uenumerate) this behaves the same as the python builtin except that it returns
an iteration of [`UInt64`](#algopy.UInt64) index values and the corresponding item.
## reversed
The `reversed()` builtin is supported when iterating within a `for` loop and behaves the same as the python builtin.
## types
See [here](./lg-types.md#python-built-in-types)