为何程序生成的员工薪资汇总报告数值全为0？

我正在完成一项课程作业程序，已接近完成，但在第96行及后续代码中，尝试生成员工信息汇总报告时，所有汇总数值均被设为0，且无回溯错误。以下是程序代码：

from Data import Employee
import queue
import csv

#Initialize Queues
input_queue = queue.Queue()
payStubs_queue = queue.Queue()

fields = ['ID', 'Name', 'Title', 'Hours Worked', 'Hourly Wage', 'Federal Tax Rate']

rows = [['1234', 'Franklin', 'Engineer', '2', '9.0', '.20'],
        ['5467', 'Raberto', 'Developer', '2', '9.1', '.20'],
        ['2345', 'Caity', 'FrontEnd', '2', '9.3', '.20'],
        ['1235', 'Patrick', 'FrontEnd', '1', '9.5', '.20'],
        ['3465', 'Prateek', 'Engineer', '3', '7.8', '.20'],
        ['4567', 'Alberto', 'Engineer', '2', '9.1', '.20'],
        ['5678', 'Orin', 'Engineer', '2', '9.0', '.20'],
        ['1678', 'Eric', 'Developer', '2', '9.1', '.20'],
        ['7565', 'Jose', 'FrontEnd', '2', '9.3', '.20'],
        ['5677', 'Alberto', 'FrontEnd', '1', '9.5', '.20'],
        ['7325', 'Alfred', 'Engineer', '3', '7.8', '.20'],
        ['9043', 'Albert', 'Engineer', '2', '9.1', '.20'],
        ['3065', 'Sarah', 'FrontEnd', '1', '9.5', '.20'],
        ['9042', 'John', 'Engineer', '3', '7.8', '.20'],
        ['2346', 'Tyler', 'Engineer', '2', '9.1', '.20']]

filename = "EmployeeInfo.csv"


'''Writing to the File.'''
try:
    with open(filename, 'w', newline='') as csv_file:
        csv_writer = csv.writer(csv_file)
        csv_writer.writerow(fields)
        csv_writer.writerows(rows)
except IOError:
    print("This file does not exist.")
except Exception as err:
    print(f"Unexpected error opening {filename} is",repr(err))
except OSError:
    print(f"OS error occurred trying to open {filename}")


'''Reading the File.'''
try:
    '''with open('EmployeeInfo.csv') as csv_file:
        csv_reader = csv.reader(csv_file)
        for line in csv_file:
            emp_id, first_name, job_title, hours_worked, hourly_wage, federal_tax_rate = (field.strip() for field in line.split(","))'''
    with open('EmployeeInfo.csv') as csv_file:
        cvsRead = csv.reader(csv_file)
        
        next(csv_file, None)
        for line in cvsRead:
            emp_id, first_name, job_title, hours_worked, hourly_wage, federal_tax_rate = (field.strip() for field in line)
            employee = Employee(emp_id, first_name, job_title, float(hours_worked), float(hourly_wage), float(federal_tax_rate))
            input_queue.put(employee)
except IOError:
    print("This file does not exist.")
except Exception as err:
    print(f"Unexpected error opening {filename} is",repr(err))
except OSError:
    print(f"OS error occurred trying to open {filename}")


'''Process data from the input queue and enqueue pay stubs into the payStubs queue.'''
while not input_queue.empty():
    employee = input_queue.get()
    gross_pay = employee.calculate_gross_pay()
    federal_tax = employee.calculate_federal_tax()
    
    state_tax = 0.1 * gross_pay
    social_security_tax = 0.05 * gross_pay
    medicare_tax = 0.02 * gross_pay
    
    net_pay = gross_pay - (federal_tax + state_tax + social_security_tax + medicare_tax)
    
    pay_stub = (employee.emp_id, f'{employee.first_name}', gross_pay, federal_tax, state_tax, social_security_tax, medicare_tax, net_pay)
    payStubs_queue.put(pay_stub)


'''Saves pay stub into text file.'''
try:
    with open('Covington.txt', 'w') as output_file:
        while not payStubs_queue.empty():
            pay_stub = payStubs_queue.get()
            output_file.write(','.join(map(str, pay_stub)) + '\n')
except IOError:
    print("This file does not exist.")
except Exception as err:
    print(f"Unexpected error opening {filename} is",repr(err))
except OSError:
    print(f"OS error occurred trying to open {filename}")


'''Generates a summary report.'''
total_gross_pay = 0
total_federal_tax = 0
total_state_tax = 0
total_social_security_tax = 0
total_medicare_tax = 0

try:
    with open('summary.txt', 'w') as summary_file:
        while not payStubs_queue.empty():
            pay_stub = payStubs_queue.get()
            total_gross_pay += pay_stub[2]
            total_federal_tax += pay_stub[3]
            total_state_tax += pay_stub[4]
            total_social_security_tax += pay_stub[5]
            total_medicare_tax += pay_stub[6]
            
            summary_file.write(f'Employee ID: {pay_stub[0]}, Employee Name: {pay_stub[1]}, Net Pay: {pay_stub[7]}\n')
except IOError:
    print("This file does not exist.")
except Exception as err:
    print(f"Unexpected error opening {filename} is",repr(err))
except OSError:
    print(f"OS error occurred trying to open {filename}")

try:
    with open('summary.txt', 'w') as summary_file:
        summary_file.write(f'Total Gross Pay for All Employees: {total_gross_pay}\n')
        summary_file.write(f'Total Federal Taxes Withheld for All Employees: {total_federal_tax}\n')
        summary_file.write(f'Total State Taxes Withheld for All Employees: {total_state_tax}\n')
        summary_file.write(f'Total Social Security Withheld for All Employees: {total_social_security_tax}\n')
        summary_file.write(f'Total Medicare Amount Withheld for All Employees: {total_medicare_tax}\n')
except IOError:
    print("This file does not exist.")
except Exception as err:
    print(f"Unexpected error opening {filename} is",repr(err))
except OSError:
    print(f"OS error occurred trying to open {filename}")

#Prints summary to the screen
print(f'Total Gross Pay for All Employees: {total_gross_pay}\n')
print(f'Total Federal Taxes Withheld for All Employees: {total_federal_tax}\n')
print(f'Total State Taxes Withheld for All Employees: {total_state_tax}\n')
print(f'Total Social Security Withheld for All Employees: {total_social_security_tax}\n')
print(f'Total Medicare Amount Withheld for All Employees: {total_medicare_tax}\n')

问题原因 #

核心问题是**payStubs_queue队列在生成Covington.txt时已被完全取空**：
在"Saves pay stub into text file"代码块中，while not payStubs_queue.empty()循环会取出队列中所有的薪资存根并写入文件，执行完毕后队列变为空。后续生成汇总报告时，再次遍历空队列，没有任何数据可以累加，导致所有total_*变量保持初始值0。

另外，原代码中两次用'w'模式打开summary.txt，第二次写入会直接覆盖第一次的员工明细内容，这也是需要修复的问题。

修复方案 #

方案一：用列表存储薪资数据（推荐） #

在生成薪资存根时，同时存入一个列表，后续所有操作都基于这个列表，避免队列被取空的问题：

1. 修改数据处理部分，新增列表存储薪资存根：

# 新增列表存储所有薪资存根
pay_stubs_list = []

'''Process data from the input queue and enqueue pay stubs into the payStubs queue.'''
while not input_queue.empty():
    employee = input_queue.get()
    gross_pay = employee.calculate_gross_pay()
    federal_tax = employee.calculate_federal_tax()
    
    state_tax = 0.1 * gross_pay
    social_security_tax = 0.05 * gross_pay
    medicare_tax = 0.02 * gross_pay
    
    net_pay = gross_pay - (federal_tax + state_tax + social_security_tax + medicare_tax)
    
    pay_stub = (employee.emp_id, f'{employee.first_name}', gross_pay, federal_tax, state_tax, social_security_tax, medicare_tax, net_pay)
    payStubs_queue.put(pay_stub)
    pay_stubs_list.append(pay_stub)  # 将存根加入列表

2. 修改保存薪资文件的代码，遍历列表而非队列：

'''Saves pay stub into text file.'''
try:
    with open('Covington.txt', 'w') as output_file:
        for pay_stub in pay_stubs_list:
            output_file.write(','.join(map(str, pay_stub)) + '\n')
except IOError:
    print("This file does not exist.")
except Exception as err:
    print(f"Unexpected error opening {filename} is",repr(err))
except OSError:
    print(f"OS error occurred trying to open {filename}")

3. 修改汇总报告代码，用列表计算并合并写入逻辑（避免覆盖）：

'''Generates a summary report.'''
total_gross_pay = 0
total_federal_tax = 0
total_state_tax = 0
total_social_security_tax = 0
total_medicare_tax = 0

try:
    with open('summary.txt', 'w') as summary_file:
        # 写入员工明细并计算汇总
        for pay_stub in pay_stubs_list:
            total_gross_pay += pay_stub[2]
            total_federal_tax += pay_stub[3]
            total_state_tax += pay_stub[4]
            total_social_security_tax += pay_stub[5]
            total_medicare_tax += pay_stub[6]
            
            summary_file.write(f'Employee ID: {pay_stub[0]}, Employee Name: {pay_stub[1]}, Net Pay: {pay_stub[7]}\n')
        
        # 写入汇总数据
        summary_file.write('\n')
        summary_file.write(f'Total Gross Pay for All Employees: {total_gross_pay}\n')
        summary_file.write(f'Total Federal Taxes Withheld for All Employees: {total_federal_tax}\n')
        summary_file.write(f'Total State Taxes Withheld for All Employees: {total_state_tax}\n')
        summary_file.write(f'Total Social Security Withheld for All Employees: {total_social_security_tax}\n')
        summary_file.write(f'Total Medicare Amount Withheld for All Employees: {total_medicare_tax}\n')
except IOError:
    print("This file does not exist.")
except Exception as err:
    print(f"Unexpected error opening {filename} is",repr(err))
except OSError:
    print(f"OS error occurred trying to open {filename}")

方案二：调整执行顺序 #

如果必须使用队列，可以先执行汇总计算，再生成Covington.txt文件，确保队列数据先用于汇总再被取出写入文件。

内容的提问来源于stack exchange，提问作者fskiddles