Python 原始输入中的命令定义功能?

Python 原始输入中的命令定义功能?,python,csv,Python,Csv,我有一个def函数,看起来像: def update(marks, num, mark, column): lines = [l for l in marks] for row in range(len(all_marks)): if all_marks[row][0] == num: lines[row][column] = mark elif lines[row][column] != '': p

我有一个def函数,看起来像:

def update(marks, num, mark, column):
    lines = [l for l in marks]
    for row in range(len(all_marks)):
        if all_marks[row][0] == num:
            lines[row][column] = mark
        elif lines[row][column] != '':
            print num + ' already has a value in column - update ignored.'
result1 = raw_input('Enter results file: ')
num = raw_input('Student number (empty to finish): ')

if len(snumber) == 0:
    print
    print
    print 'finished'
    print
    print
    return interact()

 else:
    pass

 column2 = raw_input('Enter column: ')
 newresult1 = raw_input('New result: ')

 try:
     print update(result1, snumber, newresult1, column2)

 except IOError:
    print 'Try again'
另一个def函数中的原始输入函数如下所示:

def update(marks, num, mark, column):
    lines = [l for l in marks]
    for row in range(len(all_marks)):
        if all_marks[row][0] == num:
            lines[row][column] = mark
        elif lines[row][column] != '':
            print num + ' already has a value in column - update ignored.'
result1 = raw_input('Enter results file: ')
num = raw_input('Student number (empty to finish): ')

if len(snumber) == 0:
    print
    print
    print 'finished'
    print
    print
    return interact()

 else:
    pass

 column2 = raw_input('Enter column: ')
 newresult1 = raw_input('New result: ')

 try:
     print update(result1, snumber, newresult1, column2)

 except IOError:
    print 'Try again'
底部的第三行应该打印def update(marks、num、mark、column),但它始终不返回任何值

对不起,代码有点乱。 有人能告诉我我做错了什么吗

提前感谢。

原始输入()提示用户并以字符串形式返回用户的响应。您可能希望将字符串转换为整数

此代码将提醒用户直到给出正确的响应:

while True:
  try:
    column2 = int(raw_input('Enter column: '))
    break
  except ValueError:
    print 'You did not supply an integer!'

您的
update
函数看起来并没有返回任何内容。您需要显式返回某些内容,否则将不会有返回值