Question

执行包含用.ix切片的df切片的Python代码，我收到有关其未来弃用的警告。我一直在寻找替代品。但是我一生都无法使代码正常工作。

我已经遵循了这个答案 pandas iloc vs ix vs loc explanation, how are they different? 还有更多

如果尝试使用.loc切片删除两行，并用上面使用.ix的行替换，您可能会看到代码正常工作。

请帮助。

我的代码可从美国联邦储备银行获取最新汇率。

module = __name__

import pandas as pd
pd.core.common.is_list_like = pd.api.types.is_list_like
from pandas_datareader import data as web
import numpy as np
import datetime

xratelist = ['DEXDNUS', 'DEXUSEU']
xrts = []


def xRateList_pd(xratelist, modus='sim'):
    years = 1.2
    days = int(252 * years)  # ant. arb. dage pr år = 252

    if modus == 'sim':
        start   = datetime.datetime(2016,1,1)  # indstil manuelt
        end     = datetime.datetime(2018,5,18) # indstil manuelt

    if modus == 'trading':
        end     = pd.Timestamp.utcnow()
        start   = end - days * pd.tseries.offsets.BDay()

    # Pick all rates simultaneously
    print('Fetching xratelist from Fred: ', xratelist)
    for xrt in xratelist:
        r = web.DataReader(xrt, 'fred',
                       start = start, end = end)
        # add a symbol column
        xrts.append(r)
    # concatenate all the dfs into one
    df_xrates = pd.concat(xrts, axis='columns')  

    df_xrates['DEXDNUS'] = np.round(df_xrates['DEXDNUS'], decimals=4)
    df_xrates['DEXUSEU'] = np.round(df_xrates['DEXUSEU'], decimals=4)


#    xrateDNUS = float(df_xrates.ix[-1, 'DEXDNUS'])  # Works but deprecated...
    xrateDNUS = float(df_xrates.loc[-1, 'DEXDNUS'])   # Finds last x-rate in pd
    xratedateDNUS = df_xrates.index[-1]  # Finds date for this xrate, index..
    print('Found xrateDNUS DKK/USD    : %1.2f DKK, from: %s' %(xrateDNUS, xratedateDNUS))

#    xrateUSEU = float(df_xrates.ix[-1, 'DEXUSEU'])  # Works but deprecated...
    xrateUSEU = float(df_xrates.loc[-1, 'DEXUSEU'])
    xratedateUSEU = df_xrates.index[-1]
    print('Found xrateUSEU USD/EUR    : %1.2f $, from: %s' %(xrateUSEU, xratedateUSEU))

    return df_xrates, xrateDNUS, xratedateDNUS, xrateUSEU, xratedateUSEU


try:
    ###  Get Xrates  =============================================================

    print('')
    print('                ==== $ ====')
    print('')
    print('Looking up DKK/USD & USD/EUR online (US Federal Reserve Bank)')  # via Federal Res. Bank (using pd DataReader)'


    df_xrates, xrateDNUS, xratedateDNUS, xrateUSEU, xratedateUSEU = xRateList_pd(xratelist, modus='trading') #,years=0.25 ,start=datetime.datetime(2000,1,1), end=pd.Timestamp.utcnow()


except: 
    print('!!! Error in module %s !!!' %(module))
    pass


if __name__ == '__main__':

    print("== m03_get_x_rates == is being run directly")
else:
    print("Importing and processing == %s == from CrystallBall" %(module))

Answer 1

谢谢大家，我很清楚我在问题中所写的.iloc的可能性。但是在我的示例中，我无法破解该方法。

好-终于2天后，我弄破了螺母。我找到了一种用.iat切片df的新方法，并且可以工作！ ew。

因此，不建议使用.ix的切片行

xrateDNUS = float(df_xrates.ix[-1, 'DEXDNUS'])  # Works but deprecated...

被这种更现代的.iat切片方式所取代

xrateDNUS = float(df_xrates.iat[-1, 0])   # Finds last x-rate in pd

，并且有效。

实际上，我也使用相同的切片引用语法使.iloc起作用

xrateDNUS = float(df_xrates.loc[-1, 0])   # Finds last x-rate in pd

奇怪的是我无法让.loc与列标签一起使用...我想知道...

xrateDNUS = float(df_xrates.iloc[-1, 'DEXDNUS'])

如果任何人都可以理解为什么.iloc不起作用，请发表评论。...

pandas .ix切片已弃用-如何更换？

1 个答案: