DEPR: correct locations to access public json/parser objects in depr message (#15909)

* DEPR: correct locations to access public json objects in depr message

* Additional corrections

Author: jorisvandenbossche

pandas/__init__.py

@@ -60,11 +60,15 @@
 # extension module deprecations
 from pandas.util.depr_module import _DeprecatedModule
 
-json = _DeprecatedModule(deprmod='pandas.json', deprmodto='pandas.io.json.libjson')
-parser = _DeprecatedModule(deprmod='pandas.parser', deprmodto='pandas.io.libparsers')
+json = _DeprecatedModule(deprmod='pandas.json',
+                         moved={'dumps': 'pandas.io.json.dumps',
+                                'loads': 'pandas.io.json.loads'})
+parser = _DeprecatedModule(deprmod='pandas.parser',
+                           removals=['na_values'],
+                           moved={'CParserError': 'pandas.errors.ParserError'})
 lib = _DeprecatedModule(deprmod='pandas.lib', deprmodto='pandas._libs.lib',
                         moved={'infer_dtype': 'pandas.api.lib.infer_dtype'})
-tslib = _DeprecatedModule(deprmod='pandas.tslib', deprmodto='pandas._libs.tslib',
+tslib = _DeprecatedModule(deprmod='pandas.tslib',
                           moved={'Timestamp': 'pandas.Timestamp',
                                  'Timedelta': 'pandas.Timedelta',
                                  'NaT': 'pandas.NaT',

pandas/tslib.py

@@ -2,7 +2,6 @@
 
 import warnings
 warnings.warn("The pandas.tslib module is deprecated and will be "
-              "removed in a future version. Please import from "
-              "the pandas or pandas.errors instead", FutureWarning, stacklevel=2)
+              "removed in a future version.", FutureWarning, stacklevel=2)
 from pandas._libs.tslib import (Timestamp, Timedelta,
                                NaT, OutOfBoundsDatetime)

pandas/util/depr_module.py

@@ -68,7 +68,7 @@ def __getattr__(self, name):
         elif self.moved is not None and name in self.moved:
             warnings.warn(
                 "{deprmod} is deprecated and will be removed in "
-                "a future version.\nYou can access {name} in {moved}".format(
+                "a future version.\nYou can access {name} as {moved}".format(
                     deprmod=self.deprmod,
                     name=name,
                     moved=self.moved[name]),