# What Excel's =T.TEST(A2:A9, B2:B9, tails, type) computes for each type, reproduced with SciPy.
import pandas as pd
from scipy import stats
d = pd.read_csv("sheet.csv")
a, b = d.A_before, d.B_after
rows = [("=T.TEST(A,B,2,1)  type 1, paired", stats.ttest_rel(a, b).pvalue),
        ("=T.TEST(A,B,2,2)  type 2, equal variance (Student)", stats.ttest_ind(a, b, equal_var=True).pvalue),
        ("=T.TEST(A,B,2,3)  type 3, unequal variance (Welch)", stats.ttest_ind(a, b, equal_var=False).pvalue),
        ("=T.TEST(A,B,1,1)  type 1, one-tailed", stats.ttest_rel(a, b).pvalue / 2)]
for label, p in rows:
    print(f"{label}: p = {p:.4f}")