class_docstr: Test common dtype coercion rules between concat and append.
class_docstr_tok: ["Test","common","dtype","coercion","rules","between","concat","and","append","."]
code: def test_concat_categorical_multi_coercion(self):
      # GH 13524
  
      s1 = Series([1, 3], dtype="category")
      s2 = Series([3, 4], dtype="category")
      s3 = Series([2, 3])
      s4 = Series([2, 2], dtype="category")
      s5 = Series([1, np.nan])
      s6 = Series([1, 3, 2], dtype="category")
  
      # mixed dtype, values are all in categories => not-category
      exp = Series([1, 3, 3, 4, 2, 3, 2, 2, 1, np.nan, 1, 3, 2])
      res = pd.concat([s1, s2, s3, s4, s5, s6], ignore_index=True)
      tm.assert_series_equal(res, exp)
      res = s1._append([s2, s3, s4, s5, s6], ignore_index=True)
      tm.assert_series_equal(res, exp)
  
      exp = Series([1, 3, 2, 1, np.nan, 2, 2, 2, 3, 3, 4, 1, 3])
      res = pd.concat([s6, s5, s4, s3, s2, s1], ignore_index=True)
      tm.assert_series_equal(res, exp)
      res = s6._append([s5, s4, s3, s2, s1], ignore_index=True)
      tm.assert_series_equal(res, exp)
  
imports: import numpy
  import pytest
  import pandas
  from pandas import Categorical, DataFrame, Index, Series
  import pandas._testing
label_desc: Use image node_id 15 for calling the TestConcatAppendCommon obj's underlying member method code with example usage: obj.test_concat_categorical_multi_coercion() without return types