第五章解答

1.长整型表示数的范围比整型更大。在python中，整型、长整型趋于统一，普通用户不用特别关注两者区别，仅当需引用C语言时需要特别注意。

2.操作符

(a)

def product(x,y):
return x * y

(b)

>>> print product(23,24)
552

3.

def result(x):
if 90 <= x <= 100:
return "A"
elif 80 <= x <= 89:
return "B"
elif 70 <= x <= 79:
return "C"
elif 60 <= x <= 69:
return "D"
else:
return "F"

4.

# -*- coding:utf-8 -*-

def year_judge(year):

if (int(year) % 4 == 0 and int(year) % 100 != 0) or int(year) % 400 == 0:
return u"该年是闰年！"
else:
return u"该年是平年！"

5.

# -*- coding:utf-8 -*-
def exchange(x):
divide_25,mod_25 = divmod(x,25)[0],divmod(x,25)[1]
if mod_25 == 0:
return u"%d 美分换算结果是：%d枚25美分。" \
% (x,divide_25)
else:
divide_10,mod_10 = divmod(mod_25,10)[0],divmod(mod_25,10)[1]
if mod_10 == 0:
return u"%d美分换算结果是：%d枚25美分，%d枚10美分。" \
% (x,divide_25,divide_10)
else:
divide_5,mod_5 = divmod(mod_10,5)[0],divmod(mod_10,5)[1]
if mod_5 == 0:
return u"%d美分换算结果是：%d枚25美分，%d枚10美分，%d枚5美分。" \
% (x,divide_25,divide_10,divide_5)
else:
return u"%d美分换算结果是：%d枚25美分，%d枚10美分，%d枚5美分,%d枚1美分。"\
% (x,divide_25,divide_10,divide_5,mod_5)

def cents_exchange(x):
if x < 1:
x = x * 100
else:
x = int(x)
print exchange(x)

6.

# -*- coding:utf-8 -*-

def calculator():
global expression
expression = raw_input("请输入一个表达式，可以计算加减乘除取余和幂运算，按Q退出。".decode("utf-8").encode("gbk"))
if expression == "Q":
return u"程序退出，再见"else:
for i in ["+","-","**","/","%","*"]:
if i in expression:
numbers = expression.split(i)
if "." in expression:
N1 = float(numbers[0])
N2 = float(numbers[1])
else:
N1 = int(numbers[0])
N2 = int(numbers[1])
if i == "+":
return N1 + N2
elif i == "-":
return N1 - N2
elif i == "*":
return N1 * N2
elif i == "**":
return N1 ** N2
elif i == "%":
return N1 % N2
elif i == "/":
return N1 / N2

while True:
print calculator()
if expression == "Q":
break

7.

# -*- coding:utf-8 -*-
sales = float(raw_input("请输入营业额".decode("utf-8").encode("gbk")))
rate = float(raw_input("请输入税率,以两位小数表示".decode("utf-8").encode("gbk")))
print u"应缴税额为：%f 元人民币。" % (sales * rate)

8.

# -*- coding:utf-8 -*-
def geometry():
prompt = raw_input("计算正方形面积请输入1，立方体体积请输入2，圆面积请输入3，球体积请输入4".\
decode("utf-8").encode("gbk"))
if prompt == "1":
side = raw_input("请输入边长".decode("utf-8").encode("gbk"))
print u"该正方形的面积是：%d" % (int(side) ** 2)
elif prompt == "2":
side = raw_input("请输入边长".decode("utf-8").encode("gbk"))
print u"该正方体的体积是：%d" % (int(side) ** 3)
elif prompt == "3":
radius = raw_input("请输入半径".decode("utf-8").encode("gbk"))
print u"该圆的面积是：%s" % (float(radius) ** 2 * 3.14)
elif prompt == "4":
radius = raw_input("请输入半径".decode("utf-8").encode("gbk"))
print u"该球的体积是：%s" % (float(radius) ** 3 * 4 * 3.14 / 3)

geometry()

9.

a.进制问题 python中0开头的数字表示八进制的数字

b.56l + 78l 代表的是长整数的和

10.

# -*- coding:utf-8 -*-
def F_to_C(F):
print u"%s℉等于%f℃" % (F,(float(F) - 32) * 5 / 9)

11.(1)

#取偶数
for i in range(0,21):
if i % 2 == 0:
print i,

print

#取奇数
for i in range(0,21):
if i % 2 == 1:
print i,

(2)对2进行取余运算，余数0是偶数，否则是奇数

(3)

# -*- coding:utf-8 -*-

def judge_divide(x,y):
if x % y == 0:
print u"%d可以被%d整除！" % (x,y)
else:
print u"%d不能被%d整除！" % (x,y)

def judge():
number1 = int(raw_input("请输入第一个整数".decode("utf-8").encode("gbk")))
number2 = int(raw_input("请输入第二个整数".decode("utf-8").encode("gbk")))
if number1 < number2:
judge_divide(number2,number1)
else:
judge_divide(number1,number2)

12.

# -*- coding:utf-8 -*-
import sys
print sys.maxint
print -sys.maxint - 1
print sys.float_info.max
print sys.float_info.min
print sys.long_info

13.

# -*- coding:utf-8 -*-
time = raw_input("请输入时间，英文冒号:前为小时数，英文冒号:后为分钟数".decode("utf-8").encode("gbk"))
hour = int(time.split(":")[0])
minute = int(time.split(":")[1])
print u"%d:%d等于%d分钟。" % (hour,minute,hour * 60 + minute)

14.

# -*- coding:utf-8 -*-
def Annual_return_rate(rate):
per_day_rate = rate / 365.0
investment = 1
interest = 1 * (1 + per_day_rate) ** 365 - 1
print u"年回报率为：",interest * 100,"%"

Annual_return_rate(0.5)

15.

# -*- coding:utf-8 -*-
def greatest_common_divisor(x,y):
divisor = max(x,y)
while divisor >= 1:
if x % divisor != 0 or y % divisor != 0:
divisor -= 1
else:
print u"%d和%d的最大公约数是%d。" % (x,y,divisor)
break

def least_common_multiple(x,y):
multiple = max(x,y)
while multiple <= x * y:
if multiple % x == 0 and multiple % y == 0:
print u"%d和%d的最小公倍数是%d。" % (x,y,multiple)
break
else:
multiple += 1

16.

家庭财务。给定一个初始金额和月开销数，使用循环，确定剩下的金额和当月的支出数，包括最后的支出数。Payment()函数会用到初始金额和月额度，输出结果应该类似下面的格式（例子中的数字仅用于演示）。

Enter opening balance: 100.00

Enter monthly payment: 16.13

Amount Remaining

Pymt# Paid Balance

----- ---- -------

0 $ 0.00 $100.00

1 $16.13 $ 83.87

2 $16.13 $ 67.74

3 $16.13 $ 51.61

4 $16.13 $ 35.48

5 $16.13 $ 19.35

6 $16.13 $ 3.22

7 $ 3.22 $ 0.00

【答案】

代码如下：

balance = float(raw_input("Enter opening balance: ... "))

payment = float(raw_input("Enter monthly payment: ... "))

pymt = 1

print ' Amount Remaining'

print 'Pymt# Paid Balance'

print '----- ------ -----------'

print '%4d%15.2f%15.2f' % (0, 0.00, 100)

while (balance - payment*pymt ) >= 0:

pymt = pymt + 1

print '%4d%15.2f%15.2f' % (pymt - 1, payment, (balance - payment*(pymt - 1)))

print '%4d%15.2f%15.2f' % (pymt, (balance - payment*(pymt - 1)), 0)

17.

# -*- coding:utf-8 -*-
import random

N = random.randint(2,100)
i = 1
random_list1 = []
while i <= N:
random_list1.append(random.randint(0,2 ** 31 - 1))
i += 1

h = 1
N2 = random.randint(1,100)
random_list2 = []
while h <= N2:
random_list2.append(random.choice(random_list1))
h += 1

print sorted(random_list2)