如何在python中写入dat文件

Question

我在一个可以轻松访问的 dat 文件中包含此内容，它不在文件的开头而是在中间。 我只插入我需要修改的文件部分。

{
  ....,
    "Rot": {
      "RM": [
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,",
        ",>=,"
      ]
    },
  .......        
}

而不是带有",>=,",我希望我可以从python代码中插入一个自定义字符串，例如"M,<=,5", ，因为我必须对许多文件/多次执行此操作。 我可以通过这个脚本读取文件，但我不明白如何在 python 代码中找到我想要更改的行以及如何在其中覆盖我感兴趣的字符串。

prefixed = [filename for filename in os.listdir('.') if filename.startswith("CRY")] #NQ, DIV, ecc..
for i in range(len(prefixed)):
    with open(prefixed[i], 'r') as file:
        lines = file.readlines()
        print(lines)

Answer 1

prefixed = [filename for filename in os.listdir('.') if filename.startswith("CRY")] #NQ, DIV, ecc..
for i in range(len(prefixed)):
    # Read lines
    file = open(prefixed[i], 'r')
    file_content = file.readlines()
    file.close()

    # Treatment
    for pos, line in enumerate(file_content):
        if ",>=," in line:
            file_content[pos] = line.replace(",>=,", "myCustomString")

    # Write lines
    file = open(prefixed[i], 'w')
    file.writelines(file_content)
    file.close()

只修改第一个元素：

prefixed = [filename for filename in os.listdir('.') if filename.startswith("CRY")] #NQ, DIV, ecc..
for i in range(len(prefixed)):
    # Read lines
    file = open(prefixed[i], 'r')
    file_content = file.readlines()
    file.close()

    # Treatment
    for pos, line in enumerate(file_content):
        if ",>=," in line:
            file_content[pos] = line.replace(",>=,", "myCustomString")
            # Add break to quit loop after first replacement
            break

    # Write lines
    file = open(prefixed[i], 'w')
    file.writelines(file_content)
    file.close()