python 核心编程课后练习(chapter 5)

5-2

1 #5-2

2 def mul(x, y):

3   return x * y

4 

5 print mul(4,5)  

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5-3

 1 #5-3

 2 def value_score(num):

 3   if 90<=num<=100:

 4     return 'A'

 5   elif 80<=num<=89:

 6     return 'B'

 7   elif 70<=num<=79:

 8     return 'C'

 9   elif 60<=num<=69:

10     return 'D'

11   elif 0<=num<=59:

12     return 'F'

13   else:

14     print "invalid value"         

15 

16 print value_score(90)

17 print value_score(1000)

18 print value_score(0) 

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5-4

 1 #5-4

 2 def Leap_year(year):

 3   if year%4 == 0 and year%100 == 0 :

 4     return True

 5   elif year%4 == 0 and year%100 != 0 :

 6     return True   

 7   else:

 8     return False

 9 

10 if Leap_year(2004):

11   print "leap year"

12 else:

13   print "common year" 

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5-5

 1 #5-5

 2 import random

 3 

 4 def least_cents(cts):

 5   left = 0

 6   sum = 0

 7 #get the coins of 25cents  

 8   sum = cts/25

 9   left = cts%25

10 #get the coins of 10cents  

11   sum += left/10

12   left = left%10

13 #get the coins of 5cents  

14   sum += left/5

15   left = left%5

16 #get the coins of 1cents  

17   sum += left

18   

19   return sum

20 

21 cents = random.randint(1, 100)

22 

23 print "%d cents will have at least: %d coins" % (cents, least_cents(cents))

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5-6

 1 #5-6

 2 

 3 def add(x, y):

 4   return x + y

 5 

 6 def sub(x, y):

 7   return x - y

 8 

 9 def mul(x, y):

10   return x * y

11 

12 def div(x, y):

13   return float(x)/float(y)      

14 

15 def mod(x, y):

16   return x % y

17 

18 def pow(x, y):

19   return x ** y

20 

21 def cal(str):

22   a = []

23   if(len(str.split('**')) == 2):

24     a = str.split('**')    

25     return pow(int(a[0]), int(a[1]))

26   elif (len(str.split('*')) == 2):

27     a = str.split('*')

28     return mul(int(a[0]), int(a[1]))

29   elif (len(str.split('%')) == 2):

30     a = str.split('%')

31     return mod(int(a[0]), int(a[1]))

32   elif (len(str.split('+')) == 2):

33     a = str.split('+')

34     return add(int(a[0]), int(a[1]))  

35   elif (len(str.split('-')) == 2):

36     a = str.split('-')

37     return sub(int(a[0]), int(a[1])) 

38   else:

39     print "Not support"  

40 

41     

42 print "enter the formula:"

43 formula_str = raw_input()          

44 print cal(formula_str)    

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5-7

1 #5-7 

2 def tax(num):

3   return num * 0.03

4 

5 turnover = raw_input("enter the turnover:")

6 print"the tax you need to turn over to the state: %f" %(tax(int(turnover)))

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5-8

 1 #5-8 

 2 import math

 3 def suqare_area(len):

 4   return float(len) * float(len)

 5 

 6 def suqare_volume(len):

 7   return float(len) ** 3

 8 

 9 def circle_area(r):

10   return math.pi * float(r) * float(r)

11 

12 def spere_volum(r):

13   return 4 * math.pi * float(r) * float(r) * float(r)/ 3.0

14   

15 

16 len = raw_input("enter the len:")

17 

18 print "the area of suqare is: %f" % suqare_area(len)

19 print "the volume of square is: %f" % suqare_volume(len)       

20 

21 r = raw_input("enter the r:")

22 print "the area of the circle is: %f" % circle_area(r) 

23 print "the volume of spere is: %f" % spere_volum(r)

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5-10

1 #5-10

2 def fah_to_centi(c):

3   return (c - 32)*(5/float(9))

4   

5 c = raw_input("enter the fahrenheit:")

6 

7 print "the centi degrees is: %f" % fah_to_centi(float(c))

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5-11

 1 #5-11

 2 def odd_num(num):

 3   return num %2 == 1

 4 

 5 def aliquant(n1, n2):

 6   return n1 % n2 == 0

 7 

 8 for e in range(0, 20):

 9   if not odd_num(e):

10     print "even number:%d" % e

11 

12 for e in range(0, 20):

13   if odd_num(e):

14     print "odd number: %d" % e  

15     

16 n1 = raw_input("enter the first number:")

17 n2 = raw_input("enter the second number:")

18 if aliquant(int(n1), int(n2)):

19   print"aliquant"

20 else:

21   print"not aliquant"  

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5-12

1 #5-12   

2 import sys

3 

4 print sys.maxint

5 print -sys.maxint - 1

6 

7 print sys.float_info.max

8 print sys.float_info.min

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5-13

1 #5-13

2 

3 def hm_to_m(str):

4   a = str.split(':')

5   return int(a[0])* 60 + int(a[1])

6   

7 hm = raw_input("enter the time:")

8 

9 print "the currents mins is: %d" % hm_to_m(hm)  

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5-14

1 #5-14

2 def year_rate():

3   return (1+0.0385)** 365 - 1.0

4 

5 print year_rate()

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5-15

 1 #5-15

 2 def GCD(m,n):

 3   if m%n == 0:

 4     return n

 5   else:

 6     return GCD(n, m%n) 

 7 

 8 def LCM(m, n):

 9   return m*n/GCD(m, n)

10 

11 m = int(raw_input("enter m:"))

12 n = int(raw_input("enter n:"))

13 

14 print"the GCD of %d, %d is: %d" % (m, n, GCD(m, n))

15 print"the LCM of %d, %d is: %d" % (m, n, LCM(m, n))  

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5-17

 1 #5-17

 2 import random

 3 

 4 N = random.randint(2, 100)

 5 a = []

 6 

 7 def show_all(a):

 8   for i in range(len(a)):

 9     print a[i]

10 

11 for i in range(0, N-1):

12   tmp = random.randint(2, 2**31)

13   a.append(tmp)

14 print "Original:"

15 show_all(a)

16 

17 for i in range(0, N-1):

18   for j in range(i, N-1):

19     if a[i] > a[j]:

20       a[i], a[j] = a[j], a[i]

21 

22 print"New arrary:"

23 show_all(a)  

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