import scipy.stats as stats
weight_high=[134,146,104,119,124,161,107,83,113,129,97,123]#平均值为120.0
weight_low=[70,118,101,85,112,132,94]#平均值为101.71
stats.mannwhitneyu(weight_high,weight_low,alternative='two-sided')#结果(statistic=62.0,pvalue=0.09934)
stats.mannwhitneyu(weight_high,weight_low,alternative='greater')#结果(statistic=62.0, pvalue=0.04967)
stats.mannwhitneyu(weight_high,weight_low,alternative='less')#结果(statistic=62.0, pvalue=0.95841)
根据python运算的结果，双边检验显示两组样本没显著差异。但是，单边检验选择小于原假设时，显著成立？这是为什么，怎么选择结论呢？求大神赐教！！！