Python 3 File readlines()用法及代码示例

描述

方法readlines()使用 readline() 读取直到 EOF 并返回包含行的列表。如果存在可选的 sizehint 参数，而不是读取到 EOF，而是读取总计大约 sizehint 字节(可能在向上舍入到内部缓冲区大小之后)的整行。

仅当立即遇到 EOF 时才返回空字符串。

用法

以下是语法readlines()方法≫

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。

示例

下面的例子展示了 readlines() 方法的用法。

Assuming that 'foo.txt' file contains following text:
This is 1st line
This is 2nd line
This is 3rd line
This is 4th line
This is 5th line

#!/usr/bin/python3

# 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 opened file
fo.close()

结果

当我们运行上面的程序时，它会产生以下结果——

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: