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Question

我必须在python 2中写一个txt.files是数字的输入:写在2行4-1和12-3中我必须做减法并将结果写到其他txt.file中

请帮帮我，我对python非常陌生，刚刚开始学习它。提前感谢你们所有人

这是我一直写到现在的内容：

    import calculator
    with open ('./expresii.txt', 'r') as f:
      line = f.readlines()
      for l in line:
        if l[1] == '-':
          print(calculator.subtraction(int(l[0]), int(l[2])))
        else:
          print(calculator.addition(int(l[0]), int(l[2])))

    with open ('./expresii.txt', 'r') as f2:
      print(f2.read())

首先我得到数字的减法，然后从第二个得到必须减去的数字。

现在如何写入新文件4-1=3和12-3=9这一定是结果

Answer 1

这是一个Python 2.7解决方案：

import re
# opens the input file in readmode
with open ('expresii.txt', 'r') as f:
    # creates an iterable of the lines in the file
    lines = f.readlines()
    # create an empty array which will store the data to write to the output file
    to_file = []
    # loops through every line in the file
    for l in lines:
        # creates a list of ints of all the numbers in that line
        nums = list(map(int, re.findall(r'\d+', l)))
        # calculate the result by subtracting the two numbers
        result = nums[0] - nums[1]
        # append answer (e.g 4-1=3) to a list, that will later be written to a file
        line = str(nums[0])+'-'+str(nums[1])+'='+str(result)+'\n'
        to_file.append(line)

#open the output file in write mode
with open('output_file.txt', 'w') as f:
    # write the to_file list to output_file.txt
    f.writelines(to_file)

此解决方案查找文件每行中的所有数字，并在减去它们时计算结果。在对输入文件中的每一行执行此操作后，它会将此数据写入输出文件。

祝您在继续学习Python的过程中一切顺利:)