Move locale code out of tm, into _config (#25757)

Author: jbrockmendel

pandas/_config/__init__.py

@@ -0,0 +1,4 @@
+"""
+pandas._config is considered explicitly upstream of everything else in pandas,
+should have no intra-pandas dependencies.
+"""

pandas/_config/localization.py

@@ -0,0 +1,93 @@
+"""
+Helpers for configuring locale settings.
+
+Name `localization` is chosen to avoid overlap with builtin `locale` module.
+"""
+from contextlib import contextmanager
+import locale
+
+
+@contextmanager
+def set_locale(new_locale, lc_var=locale.LC_ALL):
+    """
+    Context manager for temporarily setting a locale.
+
+    Parameters
+    ----------
+    new_locale : str or tuple
+        A string of the form <language_country>.<encoding>. For example to set
+        the current locale to US English with a UTF8 encoding, you would pass
+        "en_US.UTF-8".
+    lc_var : int, default `locale.LC_ALL`
+        The category of the locale being set.
+
+    Notes
+    -----
+    This is useful when you want to run a particular block of code under a
+    particular locale, without globally setting the locale. This probably isn't
+    thread-safe.
+    """
+    current_locale = locale.getlocale()
+
+    try:
+        locale.setlocale(lc_var, new_locale)
+        normalized_locale = locale.getlocale()
+        if all(x is not None for x in normalized_locale):
+            yield '.'.join(normalized_locale)
+        else:
+            yield new_locale
+    finally:
+        locale.setlocale(lc_var, current_locale)
+
+
+def can_set_locale(lc, lc_var=locale.LC_ALL):
+    """
+    Check to see if we can set a locale, and subsequently get the locale,
+    without raising an Exception.
+
+    Parameters
+    ----------
+    lc : str
+        The locale to attempt to set.
+    lc_var : int, default `locale.LC_ALL`
+        The category of the locale being set.
+
+    Returns
+    -------
+    is_valid : bool
+        Whether the passed locale can be set
+    """
+
+    try:
+        with set_locale(lc, lc_var=lc_var):
+            pass
+    except (ValueError, locale.Error):
+        # horrible name for a Exception subclass
+        return False
+    else:
+        return True
+
+
+def _valid_locales(locales, normalize):
+    """
+    Return a list of normalized locales that do not throw an ``Exception``
+    when set.
+
+    Parameters
+    ----------
+    locales : str
+        A string where each locale is separated by a newline.
+    normalize : bool
+        Whether to call ``locale.normalize`` on each locale.
+
+    Returns
+    -------
+    valid_locales : list
+        A list of valid locales.
+    """
+    if normalize:
+        normalizer = lambda x: locale.normalize(x.strip())
+    else:
+        normalizer = lambda x: x.strip()
+
+    return list(filter(can_set_locale, map(normalizer, locales)))

pandas/_libs/tslibs/ccalendar.pyx

@@ -9,6 +9,8 @@ import cython
 from numpy cimport int64_t, int32_t
 
 from locale import LC_TIME
+
+from pandas._config.localization import set_locale
 from pandas._libs.tslibs.strptime import LocaleTime
 
 # ----------------------------------------------------------------------
@@ -206,7 +208,7 @@ cpdef int32_t get_day_of_year(int year, int month, int day) nogil:
     return day_of_year
 
 
-cpdef get_locale_names(object name_type, object locale=None):
+def get_locale_names(name_type: object, locale: object=None):
     """Returns an array of localized day or month names
 
     Parameters
@@ -218,9 +220,6 @@ cpdef get_locale_names(object name_type, object locale=None):
     Returns
     -------
     list of locale names
-
     """
-    from pandas.util.testing import set_locale
-
     with set_locale(locale, LC_TIME):
         return getattr(LocaleTime(), name_type)

pandas/tests/config/__init__.py

@@ -5,9 +5,12 @@
 
 import pytest
 
+from pandas._config.localization import can_set_locale, set_locale
+
 from pandas.compat import is_platform_windows
 
-import pandas.core.common as com
+# TODO: move get_locales into localization, making `tm` import unnecessary.
+#  This is blocked by the need for core.config to be moved to _config.
 import pandas.util.testing as tm
 
 _all_locales = tm.get_locales() or []
@@ -23,30 +26,29 @@
 
 def test_can_set_locale_valid_set():
     # Can set the default locale.
-    assert tm.can_set_locale("")
+    assert can_set_locale("")
 
 
 def test_can_set_locale_invalid_set():
     # Cannot set an invalid locale.
-    assert not tm.can_set_locale("non-existent_locale")
+    assert not can_set_locale("non-existent_locale")
 
 
 def test_can_set_locale_invalid_get(monkeypatch):
-    # see gh-22129
-    #
+    # see GH#22129
     # In some cases, an invalid locale can be set,
-    # but a subsequent getlocale() raises a ValueError.
+    #  but a subsequent getlocale() raises a ValueError.
 
     def mock_get_locale():
         raise ValueError()
 
     with monkeypatch.context() as m:
         m.setattr(locale, "getlocale", mock_get_locale)
-        assert not tm.can_set_locale("")
+        assert not can_set_locale("")
 
 
 def test_get_locales_at_least_one():
-    # see gh-9744
+    # see GH#9744
     assert len(_all_locales) > 0
 
 
@@ -58,9 +60,9 @@ def test_get_locales_prefix():
 
 @_skip_if_only_one_locale
 def test_set_locale():
-    if com._all_none(_current_locale):
+    if all(x is None for x in _current_locale):
         # Not sure why, but on some Travis runs with pytest,
-        # getlocale() returned (None, None).
+        #  getlocale() returned (None, None).
         pytest.skip("Current locale is not set.")
 
     locale_override = os.environ.get("LOCALE_OVERRIDE", None)
@@ -75,14 +77,14 @@ def test_set_locale():
     enc = codecs.lookup(enc).name
     new_locale = lang, enc
 
-    if not tm.can_set_locale(new_locale):
+    if not can_set_locale(new_locale):
         msg = "unsupported locale setting"
 
         with pytest.raises(locale.Error, match=msg):
-            with tm.set_locale(new_locale):
+            with set_locale(new_locale):
                 pass
     else:
-        with tm.set_locale(new_locale) as normalized_locale:
+        with set_locale(new_locale) as normalized_locale:
             new_lang, new_enc = normalized_locale.split(".")
             new_enc = codecs.lookup(enc).name
 

pandas/tests/util/test_locale.py renamed to pandas/tests/config/test_localization.py

@@ -4,7 +4,6 @@
 from contextlib import contextmanager
 from datetime import datetime
 from functools import wraps
-import locale
 import os
 import re
 from shutil import rmtree
@@ -18,11 +17,14 @@
 import numpy as np
 from numpy.random import rand, randn
 
+from pandas._config.localization import (  # noqa:F401
+    _valid_locales, can_set_locale, set_locale)
+
 from pandas._libs import testing as _testing
 import pandas.compat as compat
 from pandas.compat import (
-    PY2, PY3, filter, httplib, lmap, lrange, lzip, map, raise_with_traceback,
-    range, string_types, u, unichr, zip)
+    PY2, PY3, httplib, lmap, lrange, lzip, map, raise_with_traceback, range,
+    string_types, u, unichr, zip)
 
 from pandas.core.dtypes.common import (
     is_bool, is_categorical_dtype, is_datetime64_dtype, is_datetime64tz_dtype,
@@ -39,7 +41,6 @@
 from pandas.core.arrays import (
     DatetimeArray, ExtensionArray, IntervalArray, PeriodArray, TimedeltaArray,
     period_array)
-import pandas.core.common as com
 
 from pandas.io.common import urlopen
 from pandas.io.formats.printing import pprint_thing
@@ -494,89 +495,6 @@ def get_locales(prefix=None, normalize=True,
     return _valid_locales(found, normalize)
 
 
-@contextmanager
-def set_locale(new_locale, lc_var=locale.LC_ALL):
-    """Context manager for temporarily setting a locale.
-
-    Parameters
-    ----------
-    new_locale : str or tuple
-        A string of the form <language_country>.<encoding>. For example to set
-        the current locale to US English with a UTF8 encoding, you would pass
-        "en_US.UTF-8".
-    lc_var : int, default `locale.LC_ALL`
-        The category of the locale being set.
-
-    Notes
-    -----
-    This is useful when you want to run a particular block of code under a
-    particular locale, without globally setting the locale. This probably isn't
-    thread-safe.
-    """
-    current_locale = locale.getlocale()
-
-    try:
-        locale.setlocale(lc_var, new_locale)
-        normalized_locale = locale.getlocale()
-        if com._all_not_none(*normalized_locale):
-            yield '.'.join(normalized_locale)
-        else:
-            yield new_locale
-    finally:
-        locale.setlocale(lc_var, current_locale)
-
-
-def can_set_locale(lc, lc_var=locale.LC_ALL):
-    """
-    Check to see if we can set a locale, and subsequently get the locale,
-    without raising an Exception.
-
-    Parameters
-    ----------
-    lc : str
-        The locale to attempt to set.
-    lc_var : int, default `locale.LC_ALL`
-        The category of the locale being set.
-
-    Returns
-    -------
-    is_valid : bool
-        Whether the passed locale can be set
-    """
-
-    try:
-        with set_locale(lc, lc_var=lc_var):
-            pass
-    except (ValueError,
-            locale.Error):  # horrible name for a Exception subclass
-        return False
-    else:
-        return True
-
-
-def _valid_locales(locales, normalize):
-    """Return a list of normalized locales that do not throw an ``Exception``
-    when set.
-
-    Parameters
-    ----------
-    locales : str
-        A string where each locale is separated by a newline.
-    normalize : bool
-        Whether to call ``locale.normalize`` on each locale.
-
-    Returns
-    -------
-    valid_locales : list
-        A list of valid locales.
-    """
-    if normalize:
-        normalizer = lambda x: locale.normalize(x.strip())
-    else:
-        normalizer = lambda x: x.strip()
-
-    return list(filter(can_set_locale, map(normalizer, locales)))
-
 # -----------------------------------------------------------------------------
 # Stdout / stderr decorators
 

pandas/util/testing.py

@@ -101,10 +101,11 @@ directory = coverage_html_report
 
 # To be kept consistent with "Import Formatting" section in contributing.rst
 [isort]
+known_pre_libs=pandas._config
 known_pre_core=pandas._libs,pandas.util._*,pandas.compat,pandas.errors
 known_dtypes=pandas.core.dtypes
 known_post_core=pandas.tseries,pandas.io,pandas.plotting
-sections=FUTURE,STDLIB,THIRDPARTY,PRE_CORE,DTYPES,FIRSTPARTY,POST_CORE,LOCALFOLDER
+sections=FUTURE,STDLIB,THIRDPARTY,PRE_LIBS,PRE_CORE,DTYPES,FIRSTPARTY,POST_CORE,LOCALFOLDER
 
 known_first_party=pandas
 known_third_party=Cython,numpy,dateutil,matplotlib,python-dateutil,pytz,pyarrow,pytest