python核心编程（第二版）-------第六章课后习题

 1 #!/usr/bin/env python
 2 #-*-coding: utf-8-*-
 3 
 4 "idcheck.py -- check the descriptor"
 5 
 6 import string
 7 import keyword
 8 
 9 alphas = string.letters + ‘_‘    #string.letters返回一个字符串，string.digits也返回一个字符串
10 nums = string.digits
11 alp_nums = alphas + nums
12 keylist = keyword.kwlist
13 
14 print "Welcome to the identifier checker 1.0"
15 
16 while True:
17     my_choice = raw_input("identifier to test?(Y or N): ")
18 
19     if my_choice != "Y" and my_choice != "N":
20         print "please choose Y or N"
21 
22     if my_choice == "N":
23         print "thanks for use! goodbye!"
24         break
25     
26     if my_choice == "Y":
27         get_input = raw_input("Please enter your identifier: ")
28         length = len(get_input)
29 
30         if length == 0:
31             print "Please enter some chars"
32 
33         if length == 1:
34             if get_input not in alphas:
35                 print "invalid identifier: the first char must be alphabetic"
36             elif get_input in keylist:
37                 print "unvalid: It is a keyword"
38             else:
39                 print "Okay as an identifier"
40 
41         if length > 1:
42             firstchar = get_input[0]
43             otherchar = get_input[1:]
44             
45             if get_input in keylist:
46                 print "unvalid: It is a keyword"   
47             elif firstchar not in alphas:
48                 print "invalid: first char must be alphabetic"
49             else:
50                 for eachchar in otherchar:
51                     if eachchar not in alp_nums:
52                         print "invalid: remaining symbols must be alphanumeric"
53                         break
54                 else:
55                     print "Okay as an identifier"
56                 print "Done!"

 1 #!/usr/bin/env python
 2 #-*-coding: utf-8-*-
 3 
 4 """a 按大小排序"""
 5 
 6 getInput = raw_input("please enter a list of number: ")
 7 getInput = getInput.split()
 8 
 9 numL = []
10 for eachNum in getInput:
11     eachNum = int(eachNum)
12     numL.append(eachNum)
13 
14 sortL = sorted(numL, reverse = True)
15 for eachNum in sortL:
16     print eachNum,

 1 #!/usr/bin/env python
 2 #-*-coding: utf-8-*-
 3 
 4 """a 按字典序（即ASCII值）排序，sorted对于字符串类型排序用的是字典序"""
 5 
 6 getInput = raw_input("please enter a list of number: ")
 7 getInput = getInput.split()
 8 
 9 sortL = sorted(getInput, reverse=True)
10 
11 for eachNum in sortL:
12     print eachNum,

 1 #!/usr/bin/env python
 2 #-*-coding: utf-8-*-
 3 
 4 def test(score):
 5     if score > 100 or score < 0:
 6         return "your input invalid"
 7     if 90 <= score <= 100:
 8         return "A"
 9     if 80 <= score <= 89:
10         return "B"
11     if 70 <= score <= 79:
12         return "C"
13     if 60 <= score <= 69:
14         return "D"
15     if score < 60:
16         return "F"
17 
18 def main():
19     L = []
20     while True:
21         getInput = raw_input("Please enter your score(press ‘q‘ to quit): ")
22         if getInput == ‘q‘:
23             break
24         getInput = float(getInput)
25         result = test(getInput)
26         if result not in "ABCDF":
27             print result
28         else:
29             print "Your score is %s"  % result
30             L.append(getInput)
31     length = len(L)
32     mean = sum(L) / length
33     print "The mean of your input is %.2f"  % mean
34 
35 if __name__ == ‘__main__‘:
36     main()

 1 #!/usr/bin/env python
 2 #-*-coding: utf-8-*-
 3 
 4 """#循环和字符串。从用户那里接受一个输入，然后逐个字符显示该字符串。下一次比前一次多一个字符"""
 5 
 6 get_input = raw_input("please enter a string: ")
 7 length = len(get_input)
 8 L = range(1, length + 1)
 9 for i in L:
10     print get_input[:i]
11 print "It‘s done!"

 1 #!/usr/bin/env python
 2 #-*-coding: utf-8-*-
 3 
 4 """#循环和字符串。从用户那里接受一个输入，然后逐个字符显示该字符串。下一次比前一次少一个字符"""
 5 
 6 get_input = raw_input("please enter a string: ")
 7 length = len(get_input)
 8 L = [None] + range(-1, -length, -1)
 9 for i in L:
10     print get_input[:i]
11 print "It‘s done!"

 1 #!/usr/bin/env python
 2 #-*-coding: utf-8-*-
 3 
 4 getInput = raw_input("Please enter two string: ")
 5 getInput = getInput.split()
 6 str1 = getInput[0].lower()
 7 str2 = getInput[1].lower()
 8 len1 = len(str1)
 9 len2 = len(str2)
10 
11 if len1 != len2:
12     print "Not equal!"
13 if len1 == len2:
14     L = range(len1)
15     for i in L:
16         if str1[i] != str2[i]:
17             print "Not equal!"
18             break
19     print "equal!"