JES:I/O操作在封闭文件错误上

Question

def calculateGrades():
  file = open(pickAFile(), "rt")
  highestGrade(file)
  lowestGrade(file)
def highestGrade (file): 
  lines= file.readlines()
  file.close   
  len_lines_file = len(lines) 
  lines = lines[1:len_lines_file]
  highest_Grade = 0.0 
  parts = lines[0].split(",")
  highest_Grade = int(parts[2]) 
  for line in lines:
    parts = line.split(",")
    if int(parts[2]) > highest_Grade:
      highest_Grade = int(parts[2])
def lowestGrade(file):
  open(file(, "rt")
  lines= file.readlines()
  file.close()
  len_lines_file = len(lines) 
  lines = lines[1:len_lines_file]
  lowest_Grade = 0.0
  parts = lines[0].split(",")
  lowest_Grade = int(parts[2]) 
  for line in lines:
    parts = line.split(",")
    if int(parts[2]) < lowest_Grade:
      lowest_Grade = int(parts[2])
  print lowest_Grade
calculateGrade()

计算Grade((是我教授所说的"霸主"功能。我正在尝试运行最低级和最高级功能中主要功能中拔出的文件，但它一直在给我o/i错误，我不确定该怎么做。

Answer 1

似乎在运行highestGrade()后立即运行lowestGrade()时，您似乎会发生错误。发生这种情况是因为您已关闭highestGrade()中的文件，但请勿在lowestGrade()中正确打开：lowestGrade()定义中的第一行应该是file = open(pickAFile(), "rt")。

。

通常，最好使用with块打开文件，例如：

with open(pickAFile(), "rt") as file:
    lines= file.readlines()
### file.close() is automatically called by Python at the end of the with block

因此，一个选项是从highestGrade和lowestGrade功能中删除打开/关闭线，然后在外部进行，例如

def calculateGrades():
  with open(pickAFile(), "rt") as file:
    highestGrade(file)
    lowestGrade(file)

但是，您可能需要考虑将parts用作lowestGrade和highestGrade的参数，然后在功能之外计算它：

def calculateGrades():
  with open(pickAFile(), "rt") as file:
    lines= file.readlines()
  len_lines_file = len(lines) 
  lines = lines[1:len_lines_file]
  parts = lines[0].split(",")
  highestGrade(parts)
  lowestGrade(parts)

必要时在highestGrade和lowestGrade中截断代码。