两个简短的python小程序

1这是一个创建一个文件,并在控制台写入行到新建的文件中.

#!/usr/bin/env python'makeTextFile.py -- create text file'import osls = os.linesep#get filenamewhile True:    fname = raw_input('Enter filename:')    if os.path.exists(fname):        print "ERROR: '%s' already exists" % fname    else:        break#get file content (text) linesall = []print "\nEnter lines('.' by itself to quit).\n"#loop until user terminates inputwhile True:    entry = raw_input('>')    if entry == '.':        break    else:        all.append(entry)#write lines to file with proper line-endingfobj = open(fname, 'w')fobj.writelines(['%s%s' % (x, ls) for x in all])fobj.close()print 'DONE!'

os.linesep表示行结尾标志, 用本地变量名ls代替它节省了时间,并减少了消耗系统资源.

用 raw_input()读入文件名

用列表all[]来保存每一行文本(它们暂时在内存中).

最后创建文件后,用writelines()把内存中的行写入打开的文件中.

2.这是一个读特定文件内容的小程序.

#!/usr/bin/env python'readTextFile.py -- read and display text file'#get filenamefname = raw_input('Enter filename: ')print#attempt to open file for readingtry:    fobj = open(fname, 'r')except IOError, e:    print "*** file open error:", eelse:    #display contents to the screen    for eachLine in fobj:        print eachLine,    fobj.close()

(1)注意:由于我们没有移除代表每行结束的行结束符，我们不得不抵制 print 语句自动生成的行结束符 －－通过在print 语句的最后加一个逗号可以达到这一目的

print 后没有逗号是这种效果:                                                                print有逗号的效果:

string1                                                                                                      string1

                                                                                                                  string2

string2                                                                                                      string3

string3

(2) try-except-else是一个新出現的语句,其中except子句是我们处理错误的地方.

注:两个程序在执行前,需要给文件增加可执行权限.

$chmod a+x filename