python核心编程第二章练习

  1 #encoding=utf-8
  2 from __future__ import division  #除法总是会返回真实的商
  3 from __future__ import unicode_literals #运行时中文编码正确
  4 #练习1 
  5 string = 'hello,world'
  6 intA = 5
  7 print 'string is %s,intA is %d' % (string,intA)
  8 
  9 #练习2
 10 print 1 + 2 * 4
 11 
 12 #练习3
 13 a = 9
 14 b = 3
 15 print a+b,a-b,a*b, a/b,a%b,a**b
 16 
 17 #练习4
 18 print 'please emter string:'
 19 c = raw_input()
 20 print  c
 21 intB = int(raw_input())
 22 print 'intB is %d' % intB
 23 
 24 #练习5
 25 i = 0
 26 while i < 11:
 27     print i
 28     i += 1  #python 没有++
 29 
 30 for j in range(11):
 31     print j
 32 
 33 #练习6   有问题   a = 输入的数据，后续程序并不是
 34 #a = 3
 35 a = raw_input()
 36 print a
 37 
 38 if a > 0:
 39     print 'a > 0'
 40 elif a == 0 :
 41     print 'a == 0'
 42 else :
 43     print 'a < 0'
 44 
 45 #问题7  
 46 string = raw_input()
 47 strlen = len(string)
 48 i = 0
 49 while i < strlen:
 50     print string[i]
 51     i += 1
 52 #for 接受可迭代对象（例如序列或迭代器）作为其参数，
 53 #每次迭代其中一个元素。与传统计数器循环不太一样
 54 for j in string:
 55     print j
 56 
 57 #问题8
 58 aList = [1, 2, 3, 4, 5]    #列表[]
 59 sum = 0
 60 i = 0
 61 while i < len(aList):
 62     sum += aList[i]
 63     i += 1
 64 print 'sum while is : %d' % sum
 65 for j in aList:
 66     sum += j
 67 print 'sum for is : %d' % sum
 68 
 69 aTuple = (1, 2, 3, 4, 5)    #元组()
 70 sum = 0
 71 i = 0
 72 while i < len(aTuple):
 73     sum += aTuple[i]
 74     i += 1
 75 print 'sum while is : %d' % sum
 76 for j in aTuple:
 77     sum += j
 78 print 'sum for is : %d' % sum
 79 
 80 sum = 0
 81 j = 0
 82 while j < 5:
 83     i = int(raw_input())
 84     sum += i
 85     j += 1
 86 print sum
 87 
 88 #问题9
 89 aList = [1, 2, 3, 4]    #列表[]
 90 sum = 0
 91 i = 0
 92 while i < len(aList):
 93     sum += aList[i]
 94     i += 1
 95 float(sum)
 96 float(len(aList))
 97 
 98 print sum
 99 print float(10 / 4)
100 print 'average is %f' % (sum/(len(aList)))
101 
102 问题10
103 python 逻辑and or not
104 a = int(raw_input())
105 while a > 100 or  a < 1:
106     print 'input error,again:'
107     a = int(raw_input())
108 print 'sucess %d' % a
109 
110 #问题11
111 print '--------------菜单项------------'
112 print '(1)取五个数的和'
113 print '(2) 取五个数的差'
114 print '(X)退出'
115 select = raw_input()
116 
117 while select != 'x':
118     select = int(select)
119     if select == 1:
120         print '求和'
121         sum = 0
122         j = 0
123         while j < 5:
124             i = int(raw_input())
125             sum += i
126             j += 1
127         print sum
128     elif select == 2 :
129         print '求均值'
130         sum = 0
131         j = 0
132         while j < 5:
133             i = int(raw_input())
134             sum += i
135             j += 1
136         print float(sum/5)
137     else :
138         print '选择错误'
139     print '--------------再次进入菜单项------------'
140     print '(1)取五个数的和'
141     print '(2) 取五个数的差'
142     print '(X)退出'
143     select = raw_input()
144 
145 #问题15
146 # print 'please enter three numbers'
147 # a = int(raw_input())
148 # b = int(raw_input())
149 # c = int(raw_input())
150 # if a > b:
151 #     temp = a
152 #     a = b
153 #     b = temp
154 # if b > c:
155 #     temp = b
156 #     b = c
157 #     c = temp
158 # if a > b:
159 #     temp = a
160 #     a = b
161 #     b = temp
162 # print '%d < %d < %d' %(a,b,c)
163 
164 #问题16
165 filename = raw_input('enter file name:')
166 fobj = open(filename,'r')
167 for x in fobj:
168     print x;
169 fobj.close()
python核心编程 第二章练习

python核心编程第二章练习
