有人能告诉我为什么这个代码没有生成任何csv文件吗？

import tabula
import pandas as pd
import re

_all_ = ['PdfFileReader', 'tabula', 'read_pdf' 'os', 're', 'csv']

def getdata():

    import PyPDF2

    # open the pdf file
    object = PyPDF2.PdfFileReader("C:/Users/Manav Trivedi/Downloads/1-800-FLOWERS.COM, Inc._Annual Report_2017_EN.pdf")

    # get number of pages
    NumPages = object.getNumPages()

    for i in range(0, NumPages):
           df1 = {'Total Assets': [], 'Total Liabilities': [], 'Current Assets': [], 'Current Liabilities': []}
           df2 = {'Revenue': [], 'Net Income': [], 'Gross Profit': [], 'Net Profit': []}
           tables = tabula.read_pdf("C:/Users/Manav Trivedi/Downloads/1-800-FLOWERS.COM, Inc._Annual Report_2017_EN.pdf", encoding='utf-8', pages="all")
           for table in tables:
                 if re.search("Total Assets", str(table)) or re.search("Total Liabilities", str(table)) or re.search("Current Assets",str(table)) or re.search("Current Liabilities", str(table)):
                    strg = str(table)
                    strg = strg.split(',')
                    for j in (0,strg):
                        if(j=='Total Assets'):
                            df1[0].extend(j+1)
                        if(j=='Total Liabilities'):
                            df1[1].extend(j+1)
                        if(j=='Current Assets'):
                            df1[2].extend(j+1)
                        if(j=='Current Liabilities'):
                            df1[3].extend(j+1)

                    df1 = pd.DataFrame.from_dict(df1)
                    df1.to_csv('Balance-sheet.csv', encoding='utf-8')

                 if re.search("Revenue", str(table)) or re.search("Net Income", str(table)) or re.search("Gross Profit",str(table)) or re.search("Net Profit", str(table)):
                    strg = str(table)
                    strg = strg.split(',')
                    for j in (0,strg):
                        if(j=='Revenue'):
                            df2[0].extend(j+1)
                        if(j=='Net Income'):
                            df2[1].extend(j+1)
                        if(j=='Gross Profit'):
                            df2[2].extend(j+1)
                        if(j=='Net Profit'):
                            df2[3].extend(j+1)

                    df2 = pd.DataFrame.from_dict(df2)
                    df2.to_csv('Income-Statement.csv', encoding='utf-8')

if __name__ == '__main__':

 getdata()