python 核心编程课后练习(chapter 3)
3-8
1 #3-8 2 "makeTextFile.py -- create text file" 3 4 import os 5 ls = os.linesep 6 7 #get filename 8 fname = raw_input() 9 while True: 10 11 if os.path.exists(fname): 12 print "ERROR: '%s' already exists" % fname 13 else: 14 break 15 all = [] 16 print "\nEnter lines ('.' by itself to quit).\n" 17 18 while True: 19 entry = raw_input('newline:') 20 if entry == '.': 21 break 22 else: 23 all.append(entry) 24 25 fobj = open(fname, 'w') 26 fobj.writelines(['%s%s' % (x, ls) for x in all]) 27 fobj.close() 28 print "DONE!"
3-10
1 #3-10 2 "readtextFile.py---read and display text" 3 import os 4 5 fname = raw_input("Enter file name:") 6 print 7 8 if os.path.exists(fname): 9 fobj = open(fname, 'r') 10 for eachline in fobj: 11 print eachline.strip() 12 fobj.close() 13 else: 14 print "file not exists!!" 15 16 #3-11 17 "readtextFile.py---read and display text" 18 19 fname = raw_input("Enter file name:") 20 print 21 22 try: 23 fobj = open(fname, 'r') 24 except IOError, e: 25 print "*** file open error: ", e 26 else: 27 for eachline in fobj: 28 print eachline.strip() 29 fobj.close()
3-12
1 #3-12 2 "readtextFile.py---read and display text" 3 import os 4 ls = os.linesep 5 6 print """Enter your option: 7 (w)create a file 8 (r)read a file 9 (others)exit 10 """ 11 12 def WriteFile(str): 13 all = [] 14 if os.path.exists(str): 15 print "ERROR: '%s' already exists" % fname 16 return 17 18 print "\nEnter lines ('.' by itself to quit).\n" 19 while True: 20 entry = raw_input('newline:') 21 if entry == '.': 22 break 23 else: 24 all.append(entry) 25 26 fobj = open(fname, 'w') 27 fobj.writelines(['%s%s' % (x, ls) for x in all]) 28 fobj.close() 29 print "DONE!" 30 31 def ReadFile(str): 32 #fname = raw_input("Enter file name:") 33 print 34 35 if os.path.exists(str): 36 fobj = open(str, 'r') 37 for eachline in fobj: 38 print eachline.strip() 39 fobj.close() 40 else: 41 print "file not exists!!" 42 43 44 opt =raw_input("your option is:") 45 46 if(opt == 'w'): 47 fname = raw_input("the file to write is: ") 48 WriteFile(fname) 49 elif opt== 'r': 50 fname = raw_input("the file to read is: ") 51 ReadFile(fname) 52 else: 53 print "exit"
3-13
1 #3-13 2 "readtextFile.py---read and display text" 3 import os 4 ls = os.linesep 5 6 print """Enter your option: 7 (w)create a file 8 (r)read a file 9 (m)modify a file 10 (others)exit 11 """ 12 13 def WriteFile(str): 14 all = [] 15 if os.path.exists(str): 16 print "ERROR: '%s' already exists" % fname 17 return 18 19 print "\nEnter lines ('.' by itself to quit).\n" 20 while True: 21 entry = raw_input('newline:') 22 if entry == '.': 23 break 24 else: 25 all.append(entry) 26 27 fobj = open(fname, 'w') 28 fobj.writelines(['%s%s' % (x, ls) for x in all]) 29 fobj.close() 30 print "DONE!" 31 32 def ReadFile(str): 33 #fname = raw_input("Enter file name:") 34 print 35 36 if os.path.exists(str): 37 fobj = open(str, 'r') 38 for eachline in fobj: 39 print eachline.strip() 40 fobj.close() 41 else: 42 print "file not exists!!" 43 44 def ModifyFile(str): 45 all = [] 46 if os.path.exists(str): 47 i = 1 48 fobj = open(str, 'r') 49 for eachline in fobj: 50 newline = eachline.strip() 51 print "line %d: %s" % (i,newline) 52 newline = raw_input("replace with:") 53 all.append(newline) 54 i+=1 55 fobj.close() 56 57 opt = raw_input("do you want to save your changes,\ny(yes) \nother(n):") 58 if opt == 'y': 59 output = open(str, 'w') 60 output.writelines(['%s%s' % (x, ls) for x in all]) 61 output.close() 62 else: 63 return 64 else: 65 print "file not exists!!" 66 67 opt =raw_input("your option is:") 68 69 if(opt == 'w'): 70 fname = raw_input("the file to write is: ") 71 WriteFile(fname) 72 elif opt== 'r': 73 fname = raw_input("the file to read is: ") 74 ReadFile(fname) 75 elif opt == 'm': 76 fname = raw_input("the file to modify is:") 77 ModifyFile(fname) 78 print "the new file content is:" 79 ReadFile(fname) 80 else: 81 print "exit"
