调用QR()函数后触发EOFError错误，寻求排查帮助

运行Python脚本时触发EOFError: EOF when reading a line，仅在调用QR()函数时出现，注释掉result_QR = QR()后脚本可正常运行。以下是报错详情、完整代码及排查解决方法：

错误详情 #

Traceback (most recent call last):
  File "C:\Users\test\PycharmProjects\scanner\test.py", line 42, in <module>
    cont = input("new start y/n: ")
       ^^^^^^^^^^^^^^^^^^^^^^^^
EOFError: EOF when reading a line

完整代码 #

import colorama

colorama.init()


def code_138():
    code_input = input("Scan Code 123: ")
    code = '990012341234567890'
    result = code_input == code
    if result == 'OK': print('CODE 138: ' + colorama.Fore.GREEN + 'TRUE' + colorama.Fore.RESET)
    print(
        'CODE 138:                  ' + colorama.Fore.RED + 'FALSE' + colorama.Fore.RESET)


def QR():
    print("Scan Code QR. Ctrl-D or Ctrl-Z to next")
    code_input = []
    while True:
        try:
            line = input()
        except EOFError:
            break
        code_input.append(line)

    code = ['SPC', '0200', '1', 'CH9300762011123456789', 'S', 'Test AG', 'Test X-Y-Z', '1', '8888',
            'xxxxx', 'CH', '', '', '', '', '', '', '', '999.00', 'EUR', '', '', '', '', '', '', '', 'NON', '',
            'Test', 'EPD']
    result = code_input == code
    if result == 'OK': print('QR-Code: ' + colorama.Fore.GREEN + 'TRUE' + colorama.Fore.RESET)
    print(
        'QR-Code:                   ' + colorama.Fore.RED + 'FALSE' + colorama.Fore.RESET)


def main():
    result_138 = code_138()
    result_QR = QR()


if __name__ == '__main__':
    main()

    while True:
        cont = input("new start y/n: ")
        cont = cont.lower()

        while cont.lower() not in ("y", "n"):
            cont = input("new start y/n ")

        if cont == "n":
            print("Send")
            break

        if cont == "y":
            print('')
            print('')
            main()

完整报错输出 #

C:\Users\test\PycharmProjects\scanner\venv\Scripts\python.exe C:\Users\vonaht\PycharmProjects\handscanner\test.py 
Scan Code 123: 123
CODE 138:                  FALSE
Scan Code QR. Ctrl-D or Ctrl-Z to next
asdf
asdf^D
QR-Code:                   FALSE
new start y/n: Traceback (most recent call last):
  File "C:\Users\test\PycharmProjects\scanner\test.py", line 43, in <module>
    cont = input("new start y/n: ")
           ^^^^^^^^^^^^^^^^^^^^^^^^
EOFError: EOF when reading a line

Process finished with exit code 1

问题原因 #

当在QR()函数中输入Ctrl-D（Linux/macOS）或Ctrl-Z（Windows）时，系统会将标准输入流标记为**EOF（文件结束）**状态。后续所有调用input()的地方都会直接抛出EOFError，因为系统认为已经没有更多输入数据了。而注释掉QR()时，没有触发EOF标记，所以后续的input()能正常工作。

另外代码还有两个逻辑错误：

1. code_138()和QR()中，result是布尔值（True/False），但判断条件写成了result == 'OK'，这个判断永远不会成立，导致绿色的TRUE永远不会输出。
2. QR()函数中即使输入正确，也会执行后面的print(FALSE)语句，因为没有else分支。

解决方案 #

方案1：修改QR()的终止方式（推荐） #

不用EOF来终止输入，改为用空行停止输入，避免标记输入流为EOF：

def QR():
    print("Scan Code QR. 输入空行结束输入")
    code_input = []
    while True:
        try:
            line = input()
            # 输入空行时终止循环
            if not line:
                break
        except EOFError:
            # 兼容意外触发EOF的情况
            break
        code_input.append(line)

    code = ['SPC', '0200', '1', 'CH9300762011123456789', 'S', 'Test AG', 'Test X-Y-Z', '1', '8888',
            'xxxxx', 'CH', '', '', '', '', '', '', '', '999.00', 'EUR', '', '', '', '', '', '', '', 'NON', '',
            'Test', 'EPD']
    result = code_input == code
    if result:
        print('QR-Code: ' + colorama.Fore.GREEN + 'TRUE' + colorama.Fore.RESET)
    else:
        print('QR-Code:                   ' + colorama.Fore.RED + 'FALSE' + colorama.Fore.RESET)

同时修正code_138()的判断逻辑：

def code_138():
    code_input = input("Scan Code 123: ")
    code = '990012341234567890'
    result = code_input == code
    if result:
        print('CODE 138: ' + colorama.Fore.GREEN + 'TRUE' + colorama.Fore.RESET)
    else:
        print('CODE 138:                  ' + colorama.Fore.RED + 'FALSE' + colorama.Fore.RESET)

方案2：在后续input()中捕获EOFError #

如果必须保留EOF终止的逻辑，需要在主循环的input()调用中捕获EOFError，避免程序崩溃：

if __name__ == '__main__':
    main()

    while True:
        try:
            cont = input("new start y/n: ")
        except EOFError:
            print("\n输入结束，退出程序")
            break
        cont = cont.lower()

        while cont not in ("y", "n"):
            try:
                cont = input("new start y/n ")
            except EOFError:
                print("\n输入结束，退出程序")
                exit()
            cont = cont.lower()

        if cont == "n":
            print("Send")
            break

        if cont == "y":
            print('')
            print('')
            main()

内容的提问来源于stack exchange，提问作者Tobi