# The two rows SPSS prints for an independent-samples t-test, plus Levene's test (mean-centred, as SPSS uses).
import pandas as pd
from scipy import stats
d = pd.read_csv("two_groups.csv")
t, c = d.value[d.group == "treated"], d.value[d.group == "control"]
lev = stats.levene(t, c, center="mean")
s = stats.ttest_ind(t, c, equal_var=True); w = stats.ttest_ind(t, c, equal_var=False)
print(f"Levene's test (mean-centred): F = {lev.statistic:.2f}, p = {lev.pvalue:.3f}")
print(f"Equal variances assumed (Student): t = {s.statistic:.2f}, df = {s.df:.0f}, p = {s.pvalue:.3f}")
print(f"Equal variances not assumed (Welch): t = {w.statistic:.2f}, df = {w.df:.2f}, p = {w.pvalue:.3f}")