Python 文件 readlines()方法

readlines()方法使用readline()读取直到EOF，并返回包含这些行的列表。如果可选的sizehint参数存在，而不是读取至EOF，将读取大约总计sizehint字节的整行（可能会经过向上舍入到内部缓冲区大小）。

只有当立即遇到EOF时，才会返回空字符串。

语法

以下是readlines()方法的语法−

fileObject.readlines( sizehint )

参数

• sizehint − 这是要从文件中读取的字节数。

返回值

此方法返回一个包含行的列表。

以下示例显示了readlines()方法的用法。

假设’foo.txt’文件包含以下文本−

This is 1st line
This is 2nd line
This is 3rd line
This is 4th line
This is 5th line

示例

# Open a file
fo = open("foo.txt", "r+")
print ("Name of the file: ", fo.name)
line = fo.readlines()
print ("Read Line: %s" % (line))
line = fo.readlines(2)
print ("Read Line: %s" % (line))

# Close the opened file
fo.close()

当我们运行上面的程序时，它产生如下的输出。

Name of the file: foo.txt
Read Line: ['This is 1st line\n', 'This is 2nd line\n',
            'This is 3rd line\n', 'This is 4th line\n',
            'This is 5th line\n']
Read Line: