MicroPython 用於儲存小型資料的 KeyValue 模組

KeyValue.py

# name: KeyValue.py, version: 0.1.2, author: paoyung.chang@gmail.com
# Copyright (c) 2022 Paoyung Chang. See the file LICENSE for copying permission. 
# License link: https://gist.github.com/paoyung/7e465ad984a6cf24024508831ec54516

import os, json

LIST = None
DEBUG = True

# 此模組會產生一個名為 _kv_ 的目錄，並將資料檔放於其中。
kvDir = "_kv_"
if kvDir not in os.listdir("/"):
	os.mkdir(kvDir)
LIST = os.listdir(kvDir)

# 顯示訊息，預設為開啟
def enableMsg(en=True):
	global DEBUG
	if en:
		DEBUG = True
	else:
		DEBUG = False
	print("debug mode:", DEBUG)
	return DEBUG

def debugMsg(arg1="", *arg2, end="\n"):
	global DEBUG
	if DEBUG:
		print(arg1, end=" ")
		#
		for arg in arg2:
			print(arg, end=" ")
		print(end=end)

def updateList():
	global LIST
	LIST = os.listdir(kvDir)
	return True

# 列出已儲存的清單
def list():
	global LIST
	return LIST

def fn(key):
	return "/{}/{}".format(kvDir, key)

# 清除所有資料
def renew(really=False):
	global LIST
	if really:
		for each in list():
			os.remove(fn(each))
		LIST = []
		return True
	return False

def loadRaw(key):
	v = None
	if key in list():
		with open(fn(key)) as f:
			v = f.read()
	return v

# 讀取
def load(key):
	v = None
	try:
		v = json.loads(loadRaw(key))
	except:
		pass
	return v

# 讀取，若無值使用給定的值並儲存
def get(key, value):
	v = load(key)
	if v is None:
		save(key, value)
		return value
	else:
		return v 

# 儲存
def save(key, value):
	if not type(key) == type('str'):
		debugMsg("key must be string type.")
		return False
	v = json.dumps(value)
	debugMsg("new:", v)
	ov = loadRaw(key)
	debugMsg("old:", ov)
	msg = 'key: {}, v: {}'.format(key, v)
	if not v == ov:
		with open(fn(key), 'w') as f:
			f.write(v)
			updateList()
		debugMsg(msg, "(update)")
		return True
	else:
		debugMsg(msg, "(keep)")
		return False

# 重新命名
def rename(key1, key2):
	if key1 in list():
		os.rename(fn(key1), fn(key2))
		updateList()
		return True
	else:
		debugMsg('key "{}" is not found.'.format(key1))
		return False

# 刪除
def rm(key):
	if key in list():
		os.remove(fn(key))
		updateList()
		return True
	else:
		debugMsg('key "{}" is not found.'.format(key))
		return False