Python 如果列不存在并出现 KeyError： "['Column'] not in index" 在 df.to_csv 中写入null

发布于12月02日

我在df.to_csv行上得了KeyError: "['CashFinancial'] not in index"分，因为‘GOOG’没有CashFinancial列.我怎么能让它在null中写下‘GOOG’的CashFinancial值呢？

import pandas as pd
from yahooquery import Ticker
symbols = ['AAPL','GOOG','MSFT'] #This will be 75,000 symbols.
header = ["asOfDate","CashAndCashEquivalents","CashFinancial","CurrentAssets","TangibleBookValue","CurrentLiabilities","TotalLiabilitiesNetMinorityInterest"]

for tick in symbols:
    faang = Ticker(tick)
    faang.balance_sheet(frequency='q')
    df = faang.balance_sheet(frequency='q')
    df.to_csv('output.csv', mode='a', index=True, header=False, columns=header)

推荐答案

关于以下几点:

if tick == "GOOG"
    df.loc[:,"CashFinancial"] = None

在将整个CashFinancial列写入CSV之前，仅当您的"Tick"为GOOG时才将其设置为"None".

您发布的示例中的完整代码类似于:

import pandas as pd
from yahooquery import Ticker
symbols = ['AAPL','GOOG','MSFT']
header = ["asOfDate","CashAndCashEquivalents","CashFinancial","CurrentAssets","TangibleBookValue","CurrentLiabilities","TotalLiabilitiesNetMinorityInterest"]

for tick in symbols:
    faang = Ticker(tick)
    faang.balance_sheet(frequency='q')
    df = faang.balance_sheet(frequency='q')#,{"symbol":[1],"asOfDate":[2],"CashAndCashEquivalents":[3],"CashFinancial":[4],"CurrentAssets":[5],"TangibleBookValue":[6],"CurrentLiabilities":[7],"TotalLiabilitiesNetMinorityInterest":[8],"marketCap":[9]}
    for column_name in header :
        if not column_name in df.columns :
            #Here, if any column is missing from the names you defined 
            #in your "header" variable, we add this column and set all 
            #it's row values to None
            df.loc[:,column_name  ] = None
    
    df.to_csv('output.csv', mode='a', index=True, header=False, columns=header)