location: add all.py, using takeout/gpslogger/ip (#237)

* location: add all.py, using takeout/gpslogger/ip, update docs

my/time/tz/common.py

@@ -10,24 +10,27 @@ Depending on the specific data provider and your level of paranoia you might exp
 - it's safer when either all of your objects are tz aware or all are tz unware, not a mixture
 - you might trust your original timezone, or it might just be UTC, and you want to use something more reasonable
 '''
-Policy = Literal[
+TzPolicy = Literal[
     'keep'   , # if datetime is tz aware, just preserve it
     'convert', # if datetime is tz aware, convert to provider's tz
     'throw'  , # if datetime is tz aware, throw exception
     # todo 'warn'? not sure if very useful
 ]
 
-def default_policy() -> Policy:
+# backwards compatibility
+Policy = TzPolicy
+
+def default_policy() -> TzPolicy:
     try:
         from my.config import time as user_config
-        return cast(Policy, user_config.tz.policy)
+        return cast(TzPolicy, user_config.tz.policy)
     except Exception as e:
         # todo meh.. need to think how to do this more carefully
         # rationale: do not mess with user's data unless they want
         return 'keep'
 
 
-def localize_with_policy(lfun: Callable[[datetime], tzdatetime], dt: datetime, policy: Policy=default_policy()) -> tzdatetime:
+def localize_with_policy(lfun: Callable[[datetime], tzdatetime], dt: datetime, policy: TzPolicy=default_policy()) -> tzdatetime:
     tz = dt.tzinfo
     if tz is None:
         return lfun(dt)