Effective file handling in Python allows for flexibility in how files are managed. Being able to open and write to files is a key characteristic because it enables users to both read data from files and save data back to them. This two-way interaction is essential for many applications, such as logging information, manipulating data, or generating output files based on user input or processing.
Opening files in write mode allows users to create new files or overwrite existing ones, facilitating dynamic data handling. Python's built-in functions, such as open(), support various modes (like 'read', 'write', and 'append'), which provide programmers with the ability to choose the appropriate level of access and control over file operations.
In contrast, the other options are restrictive and do not represent effective file handling practices. For example, limiting file operations to reading only would severely hinder the ability to interact with data persistently. Allowing files to be opened only once limits the usability and flexibility that many applications require. Lastly, requiring files to be converted to a binary format first would complicate the process unnecessarily since Python can handle text and binary files seamlessly, depending on the mode specified when opening the file.