如何在循环中更新数据框中的值？

我正在尝试逐行更新评分。我有一个球员数据框，所有数据框都以相同的评分开头。对于每场比赛，我都希望评分改变。另一个数据框包含每个匹配项的结果。

import pandas as pd

gamesdata = [['paul','tom'],['paul','lisa'],['tom','paul'],['lisa','tom'],['paul','lisa'],['lisa','tom'],['paul','tom']]

games = pd.DataFrame(gamesdata, columns = ['Winner', 'Looser'])

playersdata= ['lisa','paul','tom']

players = pd.DataFrame(playersdata, columns = ['Name'])

mean_elo = 1000 elo_width = 400 k_factor = 64

players['elo'] = mean_elo

def update_elo(winner_elo, loser_elo): expected_win = expected_result(winner_elo, loser_elo) change_in_elo = k_factor * (1-expected_win) winner_elo += change_in_elo loser_elo -= change_in_elo return winner_elo, loser_elo

def expected_result(elo_a, elo_b): expect_a = 1.0/(1+10**((elo_b - elo_a)/elo_width)) return expect_a

for index, row in games.iterrows(): winnername = row['Winner']
losername = row['Looser']
web = players['elo'].loc[players['Name'] == winnername].values[0] wIndex = players.loc[players['Name'] == winnername] #I want to return just the index, so I can update the value print(wIndex)

leb = players['elo'].loc[players['Name'] == losername].values[0]
print('Winner Elo before: ' + str(web))
winner_elo, looser_elo = update_elo(web, leb)
print('Winner Elo after: ' + str(winner_elo))
#here I want to update value
#players.at[wIndex,'elo']=winner_elo  

我正在尝试使用以下方式更新玩家表中的值

players.at[wIndex,'elo']=winner_elo
但是我很难用以下代码获取索引：

wIndex = players.loc[players['Name'] == winnername]