读写文件

文件读写过程

在 Python 中读写文件时，您需要使用 with 语句，它会在您完成后自动关闭文件，为您管理可用资源。

打开和读取文件

open 函数打开一个文件并返回相应的文件对象。

>>> with open('C:\\Users\\your_home_folder\\hi.txt') as hello_file:
...     hello_content = hello_file.read()
...
>>> hello_content
'Hello World!'

或者，您可以使用readlines()方法从文件中获取一个字符串值列表，每个文本行对应一个字符串。

>>> with open('sonnet29.txt') as sonnet_file:
...     sonnet_file.readlines()
...
# [When, in disgrace with fortune and men's eyes,\n',
# ' I all alone beweep my  outcast state,\n',
# And trouble deaf heaven with my bootless cries,\n', And
# look upon myself and curse my fate,']

您也可以逐行遍历文件：

>>> with open('sonnet29.txt') as sonnet_file:
...     for line in sonnet_file:
...         print(line, end='')
...
# When, in disgrace with fortune and men's eyes,
# I all alone beweep my outcast state,
# And trouble deaf heaven with my bootless cries,
# And look upon myself and curse my fate,

写入文件

>>> with open('bacon.txt', 'w') as bacon_file:
...     bacon_file.write('Hello world!\n')
...
# 13

>>> with open('bacon.txt', 'a') as bacon_file:
...     bacon_file.write('Bacon is not a vegetable.')
...
# 25

>>> with open('bacon.txt') as bacon_file:
...     content = bacon_file.read()
...
>>> print(content)
# Hello world!
# Bacon is not a vegetable.