Python核心编程-第十一章-习题
1.
# -*- coding:utf-8 -*- def countToFour1(): for eachNum in range(5): print eachNum, def countToFour2(n): for eachNum in range(n, 5): print eachNum, def countToFour3(n=1): for eachNum in range(n, 5):m print eachNum, def tests(f): for argu in [2, 4, 5, 'nothing']: print u'%s(%s) 输出：' % (f.__name__, argu), if argu == 'nothing': try: f() print '\n' except TypeError, e: print 'ERROR: ', e print '\n' else: try: f(argu) print '\n' except TypeError, e: print 'ERROR: ', e print '\n' tests(countToFour1) tests(countToFour2) tests(countToFour3)
2.
# -*- coding:utf-8 -*-
def add_product(*numpairs):
result = {}
for eachpair in numpairs:
num1 = eachpair[0]
num2 = eachpair[1]
addresult = '%d + %d' % (num1, num2)
proresult = '%d * %d' % (num1, num2)
result[addresult] = num1 + num2
result[proresult] = num1 * num2
return result
3.
# -*- coding:utf-8 -*- def max2(a, b): return a if a > b else b def min2(a, b): return a if a < b else a def my_max(*argus): if len(argus) == 0: return u"错误!必须对非空集合取最小值！" else: maxvalue = argus[0] for eachvalue in argus: if eachvalue > maxvalue: maxvalue = eachvalue return maxvalue def my_min(*argus): if len(argus) == 0: return u"错误!必须对非空集合取最小值！" else: minvalue = argus[0] for eachvalue in argus: if eachvalue < minvalue: minvalue = eachvalue return minvalue
4-5 略
6.
7.
def my_zip(*argus): return map(None,argus[0], argus[1])
8.
# -*- coding:utf-8 -*- def year_judge(year): if (int(year) % 4 == 0 and int(year) % 100 != 0) or int(year) % 400 == 0: return True else: return False def leap_list(yearlist): return filter(year_judge, yearlist) someyears = range(1999, 2201) leapyears = [year for year in someyears if year%4==0 and year%100!=0 or year%400==0] print leapyears print leap_list(someyears)
9.
def average(nums): print reduce(lambda x, y: x+y, nums)/float(len(nums))
10. '.'的意思还是不太理解，搁置
11.
# -*- coding:utf-8 -*-
import os
def file_strip(filename):
fobj = open(filename, 'r')
content = fobj.readlines()
fobj.close()
#newcontent = map(lambda string: string.strip(), content) map()实现
newcontent = [string.strip() for string in content] # 列表解析
yourchoice = int(raw_input(u'覆盖原文件还是创建新文件？覆盖原文件请输入1，创建新文件输入2：'.encode('gbk')))
if yourchoice == 1:
fobj = open(filename, 'w')
else:
file_name = os.path.splitext(filename)
fobj = open(''.join((file_name[0]+'1',file_name[1])),'w')
fobj.writelines(map(lambda string: string+'\n',newcontent))
#fobj.writelines(['%s\n' %eachline for eachline in newcontent])
fobj.close()
12.
import time def timeit(func, *nkwargs, **kwargs): t0 = time.clock() funcreturn = func(*nkwargs, **kwargs) result = (time.clock()-t0, funcreturn) return result
13.
a.
def mult(x, y): return x * y
b.
def mult(x, y): return x * y def factorial(n): if n <= 1: return 1 else: return reduce(mult, range(1, n+1))
c.
def factorial(n): if n <= 1: return 1 else: return reduce(lambda x, y: x*y, range(1, n+1))
d.
import test_11_12 def factorial_reduce(n): if n <= 1: return 1 else: return reduce(lambda x, y: x*y, range(1, n+1)) def factorial_recursion(n): if n <= 1: return 1 else: return n * factorial_recursion(n-1) def factorial_iteration(n): if n <= 1: return 1 else: result = 1 for num in range(1, n+1): result = result * num return result def test(n): funcs = (factorial_reduce, factorial_recursion, factorial_iteration) for eachfun in funcs: retval = test_11_12.timeit(eachfun, n) print '%s time is %s.' % (eachfun.__name__, retval[0])
14.
def Fibonacci(n): if n <= 1: return n else: return Fibonacci(n-1) + Fibonacci(n-2)
16.
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from __future__ import division
from operator import add, sub, mul
from random import randint, choice
def div(x, y):
return x / y
ops = {'+': add, '-': sub, '*': mul, '/': div}
MAXTRIES = 2
def doprob():
op = choice('+-/*')
nums = [randint(1, 100) for i in range(2)]
nums.sort(reverse=True)
ans = ops[op](*nums)
pr = '%d %s %d=' %(nums[0], op, nums[1])
oops = 0
while True:
try:
if int(raw_input(pr)) == ans:
print u'解对了'
break
if oops == MAXTRIES:
print u'应该是：\n%s%d' % (pr, ans)
break
else:
print u'解错了。。。再拭一次'
oops += 1
except (KeyboardInterrupt, EOFError, ValueError):
print u'无效输入。。。再试一次'
def main():
while True:
doprob()
try:
opt = raw_input(u'继续？ [Y]'.encode('gbk')).lower()
if opt and opt[0] == 'n':
break
except (KeyboardInterrupt, EOFError):
break
if __name__ == '__main__':
main()