Imports

Import forms

import math
import math as m
from math import abs
from math import abs as absolute

Using imported names

import math

def main() -> None:
    print(math.abs(-5))
    print(math.max(3, 9))
    print(math.min(3, 9))

With from:

from math import abs as magnitude

def main() -> None:
    print(magnitude(-5))
    print(magnitude(-2.5))

Modules and packages

A module is a .p4 file. A package is a directory with an __init__.p4 file.

myproject/
  main.p4
  utils.p4
  models/
    __init__.p4
    point.p4

Dotted imports:

import pkgdemo
import pkgdemo.math.ops
import pkgdemo.math.ops as ops
from pkgdemo.math.more import shift

def main() -> None:
    print(pkgdemo.package_seed)
    print(pkgdemo.math.ops.square(5))
    print(ops.square(4))
    print(shift(10))

Scoping rules

import module binds a namespace. Bare names from that module are not available without qualification.
from module import name makes name available directly.
Imported names do not leak into a flat global namespace.
Names prefixed with _ are module-private and cannot be imported.

Module-private names

_seed: int = 5

def _twice(x: int) -> int:
    return x * 2

def reveal_total() -> int:
    return _twice(_seed)

import tools

def main() -> None:
    print(tools.reveal_total())  # ok
    # print(tools._seed)         # compile error — private

Compilation model

All reachable modules are compiled into one C program. There is no separate compilation or link-time module boundary. Imports are a compile-time mechanism, not a runtime module system.