如何使用循环将函数应用于 csv 文件列表？

Question

我正在尝试遍历目录中的所有文件并向它们添加“指标”数据。我的代码可以在其中选择 1 个文件并执行此操作，但现在正试图使其适用于所有文件。问题是当我制作循环时它说

ValueError: Invalid file path or buffer object type: <class 'list'>

目标是每个循环从列表中读取另一个文件，进行更改，然后将文件保存到更改后的文件夹中。

这是不带导入的完整代码。我从列表中复制了 1 个“file_path”并在底部添加评论。

### open dialog to select file
#file_path = filedialog.askopenfilename()

###create list from dir
listdrs = os.listdir('c:/Users/17409/AppData/Local/Programs/Python/Python38/Indicators/Sentdex Tutorial/stock_dfs/')

###append full path to list
string = 'c:/Users/17409/AppData/Local/Programs/Python/Python38/Indicators/Sentdex Tutorial/stock_dfs/'
listdrs_path = [ string + x for x in listdrs]
print (listdrs_path)

###start loop, for each "file" in listdrs run the 2 functions below and overwrite saved csv.
for file in listdrs_path:
    file_path = listdrs_path

    data = pd.read_csv(file_path, index_col=0)


    ########################################
    ####function 1
    def get_price_hist(ticker):


        # Put stock price data in dataframe
        data = pd.read_csv(file_path)
        #listdr = os.listdir('Users\17409\AppData\Local\Programs\Python\Python38\Indicators\Sentdex Tutorial\stock_dfs')
        print(listdr)
        # Convert date to timestamp and make index
        data.index = data["Date"].apply(lambda x: pd.Timestamp(x))
        data.drop("Date", axis=1, inplace=True)

        return data


    df = data
    ##print(data)

    ######Indicator data#####################

    def get_indicators(data):
        # Get MACD
        data["macd"], data["macd_signal"], data["macd_hist"] = talib.MACD(data['Close'])

        # Get MA10 and MA30
        data["ma10"] = talib.MA(data["Close"], timeperiod=10)
        data["ma30"] = talib.MA(data["Close"], timeperiod=30)

        # Get RSI
        data["rsi"] = talib.RSI(data["Close"])
        return data
    #####end functions#######





data2 = get_indicators(data)
print(data2)
data2.to_csv(file_path)

###################################################

#here is an example of what path from list looks like
#'c:/Users/17409/AppData/Local/Programs/Python/Python38/Indicators/Sentdex Tutorial/stock_dfs/A.csv'

Answer 1

问题出在第 13 行和第 14 行。您的文件名在变量 file 中，但您使用的是已分配文件列表的 file_path。因此，您将获得ValueError。试试这个：

### open dialog to select file
#file_path = filedialog.askopenfilename()

###create list from dir
listdrs = os.listdir('c:/Users/17409/AppData/Local/Programs/Python/Python38/Indicators/Sentdex Tutorial/stock_dfs/')

###append full path to list
string = 'c:/Users/17409/AppData/Local/Programs/Python/Python38/Indicators/Sentdex Tutorial/stock_dfs/'
listdrs_path = [ string + x for x in listdrs]
print (listdrs_path)

###start loop, for each "file" in listdrs run the 2 functions below and overwrite saved csv.
for file_path in listdrs_path:

    data = pd.read_csv(file_path, index_col=0)


    ########################################
    ####function 1
    def get_price_hist(ticker):


        # Put stock price data in dataframe
        data = pd.read_csv(file_path)
        #listdr = os.listdir('Users\17409\AppData\Local\Programs\Python\Python38\Indicators\Sentdex Tutorial\stock_dfs')
        print(listdr)
        # Convert date to timestamp and make index
        data.index = data["Date"].apply(lambda x: pd.Timestamp(x))
        data.drop("Date", axis=1, inplace=True)

        return data


    df = data
    ##print(data)

    ######Indicator data#####################

    def get_indicators(data):
        # Get MACD
        data["macd"], data["macd_signal"], data["macd_hist"] = talib.MACD(data['Close'])

        # Get MA10 and MA30
        data["ma10"] = talib.MA(data["Close"], timeperiod=10)
        data["ma30"] = talib.MA(data["Close"], timeperiod=30)

        # Get RSI
        data["rsi"] = talib.RSI(data["Close"])
        return data
    #####end functions#######





data2 = get_indicators(data)
print(data2)
data2.to_csv(file_path)

如果有帮助，请告诉我。