Fold _make_nseq_validator into _listify_validator.

anntzer · anntzer · commit 28c7b230bbe9 · 2020-05-20T16:41:19.000+02:00
It's easy to also check the length of the value in _listify_validator;
no need to have a second nearly identical "list-validator".  Also
deprecate validate_nseq_int and validate_nseq_float as a result.
diff --git a/doc/api/api_changes_3.3/deprecations.rst b/doc/api/api_changes_3.3/deprecations.rst
@@ -238,7 +238,8 @@ The following validators, defined in `.rcsetup`, are deprecated:
 ``validate_axes_titlelocation``, ``validate_toolbar``,
 ``validate_ps_papersize``, ``validate_legend_loc``,
 ``validate_bool_maybe_none``, ``validate_hinting``,
-``validate_movie_writers``, ``validate_webagg_address``.
+``validate_movie_writers``, ``validate_webagg_address``,
+``validate_nseq_float``, ``validate_nseq_int``.
 To test whether an rcParam value would be acceptable, one can test e.g. ``rc =
 RcParams(); rc[k] = v`` raises an exception.
 
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -14,7 +14,7 @@
 """
 
 import ast
-from functools import partial, reduce
+from functools import lru_cache, reduce
 import logging
 from numbers import Number
 import operator
@@ -81,18 +81,19 @@ def __call__(self, s):
         raise ValueError(msg)
 
 
-def _listify_validator(scalar_validator, allow_stringlist=False, *, doc=None):
+@lru_cache()
+def _listify_validator(scalar_validator, allow_stringlist=False, *,
+                       n=None, doc=None):
     def f(s):
         if isinstance(s, str):
             try:
-                return [scalar_validator(v.strip()) for v in s.split(',')
-                        if v.strip()]
+                val = [scalar_validator(v.strip()) for v in s.split(',')
+                       if v.strip()]
             except Exception:
                 if allow_stringlist:
                     # Sometimes, a list of colors might be a single string
                     # of single-letter colornames. So give that a shot.
-                    return [scalar_validator(v.strip())
-                            for v in s if v.strip()]
+                    val = [scalar_validator(v.strip()) for v in s if v.strip()]
                 else:
                     raise
         # Allow any ordered sequence type -- generators, np.ndarray, pd.Series
@@ -102,11 +103,16 @@ def f(s):
             # behavior of filtering out any empty strings (behavior was
             # from the original validate_stringlist()), while allowing
             # any non-string/text scalar values such as numbers and arrays.
-            return [scalar_validator(v) for v in s
-                    if not isinstance(v, str) or v]
+            val = [scalar_validator(v) for v in s
+                   if not isinstance(v, str) or v]
         else:
-            raise ValueError("{!r} must be of type: str or non-dictionary "
-                             "iterable".format(s))
+            raise ValueError(
+                f"Expected str or other non-set iterable, but got {s}")
+        if n is not None and len(val) != n:
+            raise ValueError(
+                f"Expected {n} values, but there are {len(val)} values in {s}")
+        return val
+
     try:
         f.__name__ = "{}list".format(scalar_validator.__name__)
     except AttributeError:  # class instance.
@@ -295,6 +301,7 @@ def validate_backend(s):
     _deprecated_since="3.3")
 
 
+@cbook.deprecated("3.3")
 def _make_nseq_validator(cls, n=None, allow_none=False):
 
     def validator(s):
@@ -320,8 +327,14 @@ def validator(s):
     return validator
 
 
-validate_nseq_float = partial(_make_nseq_validator, float)
-validate_nseq_int = partial(_make_nseq_validator, int)
+@cbook.deprecated("3.3")
+def validate_nseq_float(n):
+    return _make_nseq_validator(float, n)
+
+
+@cbook.deprecated("3.3")
+def validate_nseq_int(n):
+    return _make_nseq_validator(int, n)
 
 
 def validate_color_or_inherit(s):
@@ -480,12 +493,10 @@ def validate_whiskers(s):
         return 'range'
     else:
         try:
-            v = validate_nseq_float(2)(s)
-            return v
+            return _listify_validator(validate_float, n=2)(s)
         except (TypeError, ValueError):
             try:
-                v = float(s)
-                return v
+                return float(s)
             except ValueError as e:
                 raise ValueError("Not a valid whisker value ['range', float, "
                                  "(float, float)]") from e
@@ -746,7 +757,7 @@ def validate_sketch(s):
     if s == 'none' or s is None:
         return None
     try:
-        return tuple(validate_nseq_float(3)(s))
+        return tuple(_listify_validator(validate_float, n=3)(s))
     except ValueError:
         raise ValueError("Expected a (scale, length, randomness) triplet")
 
@@ -1226,7 +1237,7 @@ def _convert_validator_spec(key, conv):
     "axes.labelcolor":    validate_color,  # color of axis label
     # use scientific notation if log10 of the axis range is smaller than the
     # first or larger than the second
-    "axes.formatter.limits": validate_nseq_int(2),
+    "axes.formatter.limits": _listify_validator(validate_int, n=2),
     # use current locale to format ticks
     "axes.formatter.use_locale": validate_bool,
     "axes.formatter.use_mathtext": validate_bool,
@@ -1351,7 +1362,7 @@ def _convert_validator_spec(key, conv):
     "figure.titleweight": validate_fontweight,
 
     # figure size in inches: width by height
-    "figure.figsize":          validate_nseq_float(2),
+    "figure.figsize":          _listify_validator(validate_float, n=2),
     "figure.dpi":              validate_float,
     "figure.facecolor":        validate_color,
     "figure.edgecolor":        validate_color,
diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
@@ -14,19 +14,21 @@
 import matplotlib.pyplot as plt
 import matplotlib.colors as mcolors
 import numpy as np
-from matplotlib.rcsetup import (validate_bool_maybe_none,
-                                validate_stringlist,
-                                validate_colorlist,
-                                validate_color,
-                                validate_bool,
-                                validate_fontweight,
-                                validate_nseq_int,
-                                validate_nseq_float,
-                                validate_cycler,
-                                validate_hatch,
-                                validate_hist_bins,
-                                validate_markevery,
-                                _validate_linestyle)
+from matplotlib.rcsetup import (
+    validate_bool,
+    validate_bool_maybe_none,
+    validate_color,
+    validate_colorlist,
+    validate_cycler,
+    validate_float,
+    validate_fontweight,
+    validate_hatch,
+    validate_hist_bins,
+    validate_int,
+    validate_markevery,
+    validate_stringlist,
+    _validate_linestyle,
+    _listify_validator)
 
 
 def test_rcparams(tmpdir):
@@ -229,7 +231,7 @@ def generate_validator_testcases(valid):
                   (1, ValueError),
                   )
          },
-        {'validator': validate_nseq_int(2),
+        {'validator': _listify_validator(validate_int, n=2),
          'success': ((_, [1, 2])
                      for _ in ('1, 2', [1.5, 2.5], [1, 2],
                                (1, 2), np.array((1, 2)))),
@@ -238,7 +240,7 @@ def generate_validator_testcases(valid):
                             (1, 2, 3)
                             ))
          },
-        {'validator': validate_nseq_float(2),
+        {'validator': _listify_validator(validate_float, n=2),
          'success': ((_, [1.5, 2.5])
                      for _ in ('1.5, 2.5', [1.5, 2.5], [1.5, 2.5],
                                (1.5, 2.5), np.array((1.5, 2.5)))),
