TST: Add Styler.where test

Author: Licht-T

pandas/tests/io/formats/test_style.py

@@ -265,6 +265,64 @@ def f(x):
  col in self.df.loc[slice_].columns)
  assert result == expected
 
+ def test_where_with_one_style(self):
+ # GH 17474
+ def f(x):
+ return x > 0.5
+
+ style1 = 'foo: bar'
+
+ result = self.df.style.where(f, style1)._compute().ctx
+ expected = dict(((r, c),
+ [style1 if f(self.df.loc[row, col]) else ''])
+ for r, row in enumerate(self.df.index)
+ for c, col in enumerate(self.df.columns))
+ assert result == expected
+
+ def test_where_subset(self):
+ # GH 17474
+ def f(x):
+ return x > 0.5
+
+ style1 = 'foo: bar'
+ style2 = 'baz: foo'
+
+ slices = [pd.IndexSlice[:], pd.IndexSlice[:, ['A']],
+ pd.IndexSlice[[1], :], pd.IndexSlice[[1], ['A']],
+ pd.IndexSlice[:2, ['A', 'B']]]
+
+ for slice_ in slices:
+ result = self.df.style.where(f, style1, style2,
+ subset=slice_)._compute().ctx
+ expected = dict(((r, c),
+ [style1 if f(self.df.loc[row, col]) else style2])
+ for r, row in enumerate(self.df.index)
+ for c, col in enumerate(self.df.columns)
+ if row in self.df.loc[slice_].index and
+ col in self.df.loc[slice_].columns)
+ assert result == expected
+
+ def test_where_subset_compare_with_applymap(self):
+ # GH 17474
+ def f(x):
+ return x > 0.5
+
+ style1 = 'foo: bar'
+ style2 = 'baz: foo'
+
+ def g(x):
+ return style1 if f(x) else style2
+
+ slices = [pd.IndexSlice[:], pd.IndexSlice[:, ['A']],
+ pd.IndexSlice[[1], :], pd.IndexSlice[[1], ['A']],
+ pd.IndexSlice[:2, ['A', 'B']]]
+
+ for slice_ in slices:
+ result = self.df.style.where(f, style1, style2,
+ subset=slice_)._compute().ctx
+ expected = self.df.style.applymap(g, subset=slice_)._compute().ctx
+ assert result == expected
+
  def test_empty(self):
  df = pd.DataFrame({'A': [1, 0]})
  s = df.style