Python - 从文件中读取整数并在操作后将其替换到同一文件中

Question

我正在尝试从文本文件中读取一个数字，将此数字加 1，然后用 python

中的新数字覆盖旧数字

file = open('group_count','w+')# opens the text file which contains a number
groupcount = file.read()    # reads the number
i = int(groupcount)     # supposed to convert the number from the text file to an interger
groupcountnew=groupcount+1  # supposed to 'add one' to that number in the text file
file.write(groupcountnew) # will write that new number to the text file, overriding the original number

它不起作用，有人可以帮忙吗！

Answer 1

这段代码应该有效：

# opening the source file
with open('group_count.txt','r') as f:
    # reading the number
    data=f.read()

    #calculating the new number
    new_data = int(data) + 1 

# writing the new number on the same file
with open('group_count.txt','w') as f:
    f.write(str(new_data))

Answer 2

只是抛出另一个答案，你可以 seek 一个文件位置，前提是你已经在 read/write more ('r+')

中打开文件

with open("groupcount", "r+") as f:
  groupcount = f.read()
  i = int(groupcount)

  f.seek(0)

  f.write(str(i+1))

注意两个答案在处理文件时都使用 with。 read 也会选择换行符，所以这只有在只有一个数字的情况下才有效。

如果您想在需要后续数据向前移动的文件中间插入内容，这将不起作用。

Python - 从文件中读取整数并在操作后将其替换到同一文件中

Python - Reading an integer from a file and replacing it on the same file after its manipulation

python-3.4