I'm doing an LRU (Least Recently Used) cache with decorator to store recently used localization, but when I call function to read it from .json file I get "NoneType" error
def loc_cache(func):
loc_cache.locale = {} # {lang:(local, count)} local:dict
loc_cache.MAXLENGTH = 5
def wrapper(key):
print(key) #this function wasn't called
if key not in loc_cache.locale.keys():
try:
locale = read_locale(key)
loc_cache.locale[key] = (locale, 1)
wrapper.locale = locale
except KeyError:
key = "en" # set default locale
wrapper(key)
else:
locale, count = loc_cache.locale[key]
loc_cache.locale[key] = (locale, count+1)
wrapper.locale = locale
return wrapper.locale
@loc_cache
def read_locale(key):
locale = read_json("./config/locale.json", key)
return locale
def auth(user:User):
locale = read_locale(user.locale)
print(locale["auth"])
return
u = User(1) # __init__ takes 1 for id
u.locale = "en"
auth(u)
I expect that it would return phrase in "en" that stores in .json file, but it says
Traceback (most recent call last):
File "main.py", line 61, in <module>
auth(u)
File "main.py", line 52, in auth
locale = read_locale(user.locale)
TypeError: 'NoneType' object is not callable
You didn't return the wrapper function form the decorator, hence Python is returning None
as usual and trying to call it when you do read_locale(user.locale)
. You need:
def loc_cache(func):
loc_cache.locale = {} # {lang:(local, count)} local:dict
loc_cache.MAXLENGTH = 5
def wrapper(key):
print(key) #this function wasn't called
if key not in loc_cache.locale.keys():
try:
locale = read_locale(key)
loc_cache.locale[key] = (locale, 1)
wrapper.locale = locale
except KeyError:
key = "en" # set default locale
wrapper(key)
else:
locale, count = loc_cache.locale[key]
loc_cache.locale[key] = (locale, count+1)
wrapper.locale = locale
return wrapper.locale
return wrapper
# Here ^^^^