Pyhton核心编程-Chap2习题-DIY

在学Python,在看《Python核心编程》的pdf，做了Chap2的题目，答案为DIY

# Filename: 2-11.py
# Author: ChrisZZ
mylist = [1, 2, 3, 4, 6]
sum = 0
for i in mylist:
    sum = sum + i
average = sum * 1.0 / len(mylist)
while True:
    print 'Here we have a list:', mylist
    option = raw_input('Whatyou gonna know(sum/average/exit)?')
    if option == 'sum':
        print 'the sum of the list is', sum
    elif option == 'average':
        print 'the average of the list is', average
    elif option == 'exit':
        print 'Bye'
        break
    else:
        print 'Wrong option.Repeat.'

# Filename: 2-5.py
# Author: ChrisZZ
i = 0
while i <= 10:
    print i
    i = i + 1

for j in range(11):
    print j

# Filename: 2-15.py
# Author: ChrisZZ
print 'Please input 3 number.'
print 'I will sort them without using sort algo'
a = float(raw_input('the first number'))
b = float(raw_input('the second number'))
c = float(raw_input('the third number'))
res1 = (a - b) * (a - c)
mylist = []
if res1 < 0:  # a is the middle
    if b > c:
        mylist = [b, a, c]
    else:
        mylist = [c, a, b]
else:
    if a > b and b > c:
        mylist = [a, b, c]
    elif a > c and c > b:
        mylist = [a, c, b]
    elif a < b and b < c:
        mylist = [c, b, a]
    elif a < c and c < b:
        mylist = [b, c, a]

print mylist

# Filename: 2-10.py
# Author: ChrisZZ
while True:
    num = float(raw_input('Enter a number in range(1,100):'))
    if num > 100 or num < 0:
        print 'not a good number. repeat.'
    else:
        print 'nice number.bye'
        break

# Filename: 2-8.py
# Author: ChrisZZ
mylist = [1, 2, 3, 4, 5]
sumW = 0
i = 0
while i < len(mylist):
    sumW = sumW + mylist[i]
    i = i + 1
print sumW

sumF = 0
for i in mylist:
    sumF = sumF + i
print sumF

# Filename: 2-7.py
# Author: ChrisZZ
s = raw_input('Enter a string:')
print 'while loop:'
i = len(s)
while i > 0:
    print s[-i]
    i = i - 1

print 'for loop:'
for ch in s:
    print ch

# Filename: 2-6.py
# Author: ChrisZZ
num = float(raw_input('Enter a number:'))
if num < .0:
    print 'Negative number'
elif num > .0:
    print 'Positive number'
else:
    print 'Zero'

　　PS：这些题目都是分开写的py脚本，自己写了另一个脚本把他们重定向到了一个叫做result.txt的文件中，习题在~/workspace/python/xiti/路径，处理的脚本在~/workspace/python/，具体如下：

# Filename: process.py
# Author: ChrisZZ
import os
prefix = "/home/chris/workspace/python/xiti/"
filenames = os.listdir(prefix)
out = open('result.txt', 'w')
for k, v in enumerate(filenames):
    f = open(prefix + v, 'r')
    out.write('# Filename: %s\n' % v)
    out.write('# Author: ChrisZZ\n')
    for eachLine in f:
        out.write(eachLine)
    f.close()
    out.write('\n')
out.close()