Pandas进阶——头歌平台答案

第1关 Pandas分组聚合

import pandas as pd
import numpy as np

#返回最大值与最小值的差
def sub(df):
    ######## Begin #######
    return df.max() - df.min()
    ######## End #######

def main():
    ######## Begin #######
    data = pd.read_csv("step1/drinks.csv")
    df = pd.DataFrame(data)
    mapping = {"wine_servings":sub,"beer_servings":np.sum}
    print(df.groupby("continent").agg(mapping))
    ######## End #######

if __name__ == '__main__':
    main()

第2关 Pandas创建透视表和交叉表

#-*- coding: utf-8 -*-
import pandas as pd

#创建透视表
def create_pivottalbe(data):
    ###### Begin ######
    return data.pivot_table(index=["day"],values=["tip"],columns=["time"],margins=True,aggfunc=sum)
    ###### End ######

#创建交叉表
def create_crosstab(data):
    ###### Begin ######
    return pd.crosstab(index=[data.day],columns=[data.time],values=data.tip,aggfunc=sum ,margins=True)
    ###### End ######

def main():
    #读取csv文件数据并赋值给data
    ###### Begin ######
    data = pd.read_csv("step2/tip.csv")
    ###### End ######
    piv_result = create_pivottalbe(data)
    cro_result = create_crosstab(data)
    print("透视表：\n{}".format(piv_result))
    print("交叉表：\n{}".format(cro_result))
    ###### End ######