Python: Count the occurence of a number being smaller than a threshold accross row

Question

I have a dataframe df with a MultIndex like this:

df.index.levels
FrozenList([[u'params', u'pvals', u'statistics', u'std'], [u'x1', u'x2', u'x3', u'x4', u'Hx5', u'adj_r2', u'r2', u'_f_test']])

You can guess that df contains an OLS output. Is there a pandas function that I can use to count how many times a number in the index pvals for each x1 x2 ... x5 is less than 0.05?

Answer 1

(df.ix["pvals"].ix[["x1", "x2", "x3", "x4", "x5"]] < 0.05).sum()

诀窍在于，当您在算术上下文中使用Python时，它们会将True转换为1，将False转换为0。