ขั้นตอนการเขียนโค้ด · การนำทางด้วย JSON Pointer

import re
def pointer_get(root, pointer):
    if not isinstance(pointer, str): raise ValueError("pointer text")
    if pointer == "": return root
    if not pointer.startswith("/"): raise ValueError("root slash")
    value = root
    for raw in pointer[1:].split("/"):
        if re.search(r"~(?![01])", raw): raise ValueError("escape")
        key = raw.replace("~1", "/").replace("~0", "~")
        if isinstance(value, dict): value = value[key]
        elif isinstance(value, list):
            if not re.fullmatch(r"0|[1-9][0-9]*", key):
                raise ValueError("array index")
            if len(key) > len(str(len(value))): raise IndexError(key)
            value = value[int(key)]
        else: raise ValueError("not a container")
    return value