Python 尝试使用dataframe字典

我在执行此代码时遇到问题：

def create_binary_nw(row):
    if row['Net_withdrawal'] <=0:
        return 0
    else:
        return 1

# a class 
class create_storages:

    def __init__(self,file1,file2):
        self.file1 = file1
        self.file2 = file2

    def open_storages(self):
        wb = load_workbook(self.file1)#load the file to a workbook
        ws = wb.sheetnames # get all the names of Excel sheets in order to construct a dictionary
        storages = {}# a dictionary
        storages = pd.read_excel(self.file1, sheet_name = None)# adding the dictionary element
        return [storages, ws]



    def complete_storages(self):
        [storages,ws] = self.open_storages()
        for i in range(len(ws)):    
            NW = storages[ws[i]]['withdrawal']-storages[ws[i]]['injection']
            storages[ws[i]].insert(7, "Net_withdrawal",NW, True)#adding the column NW NO PROBLEM
            storages[ws[i]]['Net_withdrawal_binary']= storages[ws[i]].apply(create_binary_nw(storages[ws[i]]),axis=1)#THE PROBLEM IS HERE!!!

    enter code here

     # execution
     class_storage = create_storages('storage_data.xlsx','price_data.csv')
     #[storage1,ws1] = class_storage.open_storages()
     class_storage.complete_storages()

我认为错误来自我的函数create_binary，当我将它应用于storages[ws[I]]时，它是一个数据帧字典（storages是一个字典，storages[ws[I]]是一个数据帧，它有一个名为“Net_retrach”的列，这是一列浮点数）

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谢谢你的回答。错误消息告诉你的是，如果你想比较一组值是否小于0（

错误消息告诉你的是，如果你想比较一组值是否小于0（
好，谢谢你的回答。的确，存储[ws[i]]['Net_Retraction]是数据帧的一个列，而不是数字。感谢您的回答。实际上，storages[ws[i]['Net_Retraction]是数据帧的一个列，而不是数字
> ValueError: The truth value of a Series is ambiguous. Use a.empty, 
a.bool(), a.item(), a.any() or a.all().

import numpy as np
a = np.array([1,1,0])
if a > 0: # fails here, array can't be compared with a single value
  print("yay")

storages[ws[i]]['Net_withdrawal_binary']= storages[ws[i]].apply(create_binary_nw(storages[ws[i]]),axis=1)#THE PROBLEM IS HERE!!!

storages[ws[i]]['Net_withdrawal_binary']= storages[ws[i]].apply(lambda a: create_binary_nw(a),axis=1)