Retain newline. A non-negative size argument limits the maximum number of bytes to return (an incomplete line may be returned then). Return an empty string at EOF.

读取文件的一行，保留换行符，到文件末尾返回空串。

youdao

Retain newline. A non-negative size argument limits the maximum number of bytes to return (an incomplete line may be returned then). Return an empty string at EOF.

读取文件的一行，保留换行符，到文件末尾返回空串。

youdao