f = open('file.ipynb')
print f.read()
{ "metadata": { "name": "file" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# \u6587\u4ef6\u8bfb\u5199" ] }, { "cell_type": "code", "collapsed": false, "input": [ "f = open('file.ipynb')\n", "print f.read()" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "code", "collapsed": false, "input": [ "f = open('file.txt')\n", "f.write('something')" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\u4e3a\u5b89\u5168\u8d77\u89c1, \u9ed8\u8ba4\u6587\u4ef6\u4ee5\u53ea\u8bfb\u65b9\u5f0f\u6253\u5f00. \u7528`w`\u53c2\u6570\u6307\u5b9a\u53ef\u5199\u6253\u5f00:" ] }, { "cell_type": "code", "collapsed": false, "input": [ "f = open('file.txt', 'w')\n", "f.write('something')" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## \u5173\u95ed\u6587\u4ef6\n", "\n", "\u5c1d\u8bd5\u4ece\u6587\u4ef6\u7ba1\u7406\u5668\u4e2d\u5220\u9664`file.txt`" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from IPython.display import Image\n", "Image(filename='file.png', embed=True)" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\u6253\u5f00\u7684\u6587\u4ef6\u5982\u679c\u4e0dclose, \u7cfb\u7edf\u4e0d\u4fdd\u8bc1\u4f1a\u628a\u7f13\u5b58\u4e2d\u7684\u6570\u636e\u5199\u5165\u6587\u4ef6, \u540c\u65f6\u8be5\u6587\u4ef6\u7684\u76f8\u5173\u8d44\u6e90\u4e5f\u4e0d\u4f1a\u88ab\u91ca\u653e." ] }, { "cell_type": "code", "collapsed": false, "input": [ "f = open('file.txt', 'w')\n", "f.write('something')\n", "f.close()" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## \u66f4\u591a\u6587\u4ef6\u64cd\u4f5c\n", "\n", "\u68c0\u67e5\u6587\u4ef6\u662f\u5426\u5b58\u5728:" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from os.path import exists\n", "print exists('file.txt')" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\u8f93\u51fa\u6587\u4ef6\u4fee\u6539\u65e5\u671f:" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import os\n", "print os.path.getmtime('file.txt')" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "\u4e0a\u9762\u7684\u65f6\u95f4\u662f\u4ece[epoch](https://en.wikipedia.org/wiki/Epoch_(reference_date))\u4ee5\u6765\u7684\u79d2\u6570. \u53ef\u4ee5\u7528`time`\u6a21\u5757\u8f6c\u5316\u4e3a\u53ef\u8bfb\u7684\u5f62\u5f0f:" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import time\n", "print time.ctime(os.path.getmtime('file.txt'))" ], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }
f = open('file.txt')
f.write('something')
--------------------------------------------------------------------------- IOError Traceback (most recent call last) <ipython-input-2-275dc47d5c28> in <module>() 1 f = open('file.txt') ----> 2 f.write('something') IOError: File not open for writing
为安全起见, 默认文件以只读方式打开. 用w
参数指定可写打开:
f = open('file.txt', 'w')
f.write('something')
尝试从文件管理器中删除file.txt
from IPython.display import Image
Image(filename='file.png', embed=True)
打开的文件如果不close, 系统不保证会把缓存中的数据写入文件, 同时该文件的相关资源也不会被释放.
f = open('file.txt', 'w')
f.write('something')
f.close()
检查文件是否存在:
from os.path import exists
print exists('file.txt')
True
输出文件修改日期:
import os
print os.path.getmtime('file.txt')
1373306843.94
上面的时间是从epoch以来的秒数. 可以用time
模块转化为可读的形式:
import time
print time.ctime(os.path.getmtime('file.txt'))
Tue Jul 09 02:07:23 2013