python核心编程第九章_文件系统的一个程序

#-*-coding:utf-8-*-
import os
for tmpdir in (r'E:\python\core_program\practice\core_code\chap_9',r'E:\python'):
if os.path.isdir(tmpdir):        //判断制定路径是否存在且为一个目录
break

else:
print 'no temp directory available'
tmpdir = ''

if tmpdir:
os.chdir(tmpdir)                //改变当前工作目录至tmpdir目录中

cwd = os.getcwd()		    //获取当前文件目录路径
print '***current temporar directory***'
print cwd

print '***creating example directory...'
os.mkdir('example')            //创建一个新的工作目录
os.chdir('example')            //同样的，改变当前目前至example文件夹中
cwd = os.getcwd()
print '***new workding directory:'
print cwd
print '***original directory listing:'
print os.listdir(cwd)          //列出指定目录的文件
print "***creating test file ..."
fobj = open('test','w')
fobj.write('foo\n')
fobj.write('bar\n')
fobj.close()
print "***updated directory listing:"
print os.listdir(cwd)

print "*** renaming 'test' to 'filetest.txt'"
os.rename('test','filetest.txt')
print "***updated directory listing:"
print os.listdir(cwd)

path = os.path.join(cwd,os.listdir (cwd)[0]) // 我将cwd[0]打印出来，是盘符E，不太懂！
print '***full file pathname'
print path
print "***(pathname,basename) =="
print os.path.split(path) //把文件目录和文件分开组成二元元组
print "***(filename,extension) =="
print os.path.splitext(os.path.basename(path)) //将整个文件名和目录联合起来，而将后缀名分开

print "***displaying file contents:"
fobj = open(path)
for eachLine in fobj:
print eachLine,
fobj.close()

print "*** deleting test file "
os.remove(path)
print "***updated directory listing:"
print os.listdir(cwd)
os.chdir(os.pardir)
print "*** deleting test directory"
os.rmdir('example')
print "***DONE"

os.path.join(path1[, path2[, ...]])
将多个路径组合后返回，第一个绝对路径之前的参数将被忽略。
>>> os.path.join('c:\\', 'csv', 'test.csv')
'c:\\csv\\test.csv'
>>> os.path.join('windows\temp', 'c:\\', 'csv', 'test.csv')
'c:\\csv\\test.csv'
>>> os.path.join('/home/aa','/home/aa/bb','/home/aa/bb/c')
'/home/aa/bb/c'