import numpy as npimport pandas as pddf = pd.DataFrame(np.random.randint(0,100,100), columns=['score'])# 以所在区间作为标签。如 x=5，返回：'[0-10]'def make_label(x, step=10):    m = x // step    return '[{}-{}]'.format(m * step, (m+1) * step)        #df['level'] = df['score'].map(make_label)df['level'] = df['score'].map(lambda x:make_label(x,step=10)) # 改变区间长度为15res = df.groupby('level').size()print(df.head())print(res)