为什么在Python中使用方差分析显示形状不对齐？

Question

基于这个问题enter link description here，我使用statsmodels在python中实现ANOVA。我的数据在Pandas数据框中，country是一个范畴变量。在

def anova(data):

    mod = ols('C(country) ~ playerRank+playerGames', data=data).fit()
    aov_table = sm.stats.anova_lm(mod, typ=2)
    print aov_table

当我使用上述函数时，它显示：

^{pr2}$

编辑：

我试着做风箱：

y, X = dmatrices('CountryCode ~ playerRank+playerGames', data=data[[['playerRank', 'playerGames', 'CountryCode']]], return_type='dataframe')
mod = sm.OLS(y, X)
res = mod.fit()
res.summary()

aov_table = sm.stats.anova_lm(res, typ=2)
print aov_table

并显示以下错误：

    Traceback (most recent call last):
  File "C:\ProgramData\Anaconda2\lib\site-packages\IPython\core\interactiveshell.py", line 2881, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-13-e9f27287c5da>", line 1, in <module>
    aov_table = sm.stats.anova_lm(res, typ=2)
  File "C:\ProgramData\Anaconda2\lib\site-packages\statsmodels\stats\anova.py", line 326, in anova_lm
    return anova_single(model, **kwargs)
  File "C:\ProgramData\Anaconda2\lib\site-packages\statsmodels\stats\anova.py", line 68, in anova_single
    design_info = model.model.data.design_info
AttributeError: 'PandasData' object has no attribute 'design_info'