python核心编程 第二版 第二章 习题

初学python，将自己练习的代码发在这存着，若有人看到，希望不吝赐教。~

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2-5a:

i = 0while i <= 10:print ii = i + 1 

2-5b:

for i in range(0,11):print i

2-6:

a = 100print "Is a greater than 0?"print a > 0# ------------------------------------------------- #input = int(raw_input('Input your number >> '))if input > 0:print "Input is Positive."elif input < 0:print "Input is Negative."elif input == 0:print "Input is Zero."

2-7:

input = str(raw_input("print your string >> "))i = 0len = len(input)while i < len:print input[i],i = i + 1printfor char in input:print char,

2-8:

a_list = [1, 2, 3, 4, 5]a_tuple = [11.2, 2.2, 0.33, 1.44, 25.5]b = sum(a_list) / float(len(a_list))c = sum(a_tuple) / float(len(a_tuple))print bprint c

2-9:

a_list = [1, 2, 3, 4, 5]a_tuple = [11.2, 2.2, 0.33, 1.44, 25.5]b = sum(a_list) / float(len(a_list))c = sum(a_tuple) / float(len(a_tuple))print bprint c

2-10:

while True:input = int(raw_input("Print your number >> "))if 1 <= input <= 100:print "All right."breakelse:print "ERROR!"print "Choose another one."

2-11:

a_list = []i = 0while i < 5:input = int(raw_input('Print your number >> '))a_list.append(input)i += 1#------------------------------------#len = len(a_list)sum = sum(a_list)average = sum / float(len)#------------------------------------#while True:print '''(s)um the number(a)verage the number (q)uit the manu '''# breakchoice = str(raw_input('your choice is >> '))if choice in 'saq':if choice == 's':print "The sum is ", sumelif choice == 'a':print "The average is ", averageelse:print "Thanks for using."print "Bye!"breakelse:print "I don't know."print "Try again!"

2-15:(这段是从网上摘录的，自己写起来毫无头绪。。）

SortList = [0, 1, 2]for i in range(0,3):    print 'Please input the No.', i+1, 'number to be sort'    SortList[i] = float(raw_input())print SortList if SortList[0] < SortList[1]:    i = SortList[0]    SortList[0] = SortList[1]    SortList[1] = iif SortList[0] < SortList[2]:    i = SortList[0]    SortList[0] = SortList[2]    SortList[2] = i    if SortList[1] < SortList[2]:    i = SortList[1]    SortList[1] = SortList[2]    SortList[2] = i     print SortList