Python基础-文件的基本操作

Posted 2020-10-10

测试文件fansik内容如下：
This is line 1
This is line 2
This is line 3
This is line 4
This is line 5
This is line 6

文件的操作方法：
def open(file, mode=‘r‘, buffering=None, encoding=None, errors=None, newline=None, closefd=True):

文件打开方式如下：
========= ===============================================================
Character Meaning
--------- ---------------------------------------------------------------
‘r‘       open for reading (default)
‘w‘       open for writing, truncating the file first
‘x‘       create a new file and open it for writing
‘a‘       open for writing, appending to the end of the file if it exists
‘b‘       binary mode
‘t‘       text mode (default)
‘+‘       open a disk file for updating (reading and writing)
‘U‘       universal newline mode (deprecated)
========= ===============================================================

文件读操作：

f = open(‘fansik‘, ‘r‘, encoding=‘utf8‘)
print(f.read())
f.close()

读取整个文件内容，结果如下：

This is line 1
This is line 2
This is line 3
This is line 4
This is line 5
This is line 6

f = open(‘fansik‘, ‘r‘, encoding=‘utf8‘)
print(f.readline())
f.close()

读取整个文件第一行内容，结果如下：
This is line 1

f = open(‘fansik‘, ‘r‘, encoding=‘utf8‘)
print(f.readlines())
f.close()

    读取整个文件内容，以列表方式显示，结果如下：

[‘This is line 1\n‘, ‘This is line 2\n‘, ‘This is line 3\n‘, ‘This is line 4\n‘, ‘This is line 5\n‘, ‘This is line 6‘]


同时操作多个文件(一下方式操作文件是可以不加f.close())：

number = 0
with open(‘fansik‘, ‘r‘, encoding=‘utf8‘) as f, open(‘fansik1‘, ‘w‘, encoding=‘utf8‘) as f1:
    for line in f:
        number += 1
        if number == 5:
            line = ‘‘.join([line.strip(), ‘fanjinbao\n‘])
        f1.write(line)

fansik1文件内容如下：
This is line 1
This is line 2
This is line 3
This is line 4
This is line 5fanjinbao
This is line 6