实例一、温度转换
温度刻画的两种不同体系，是摄氏度和华氏度，
摄氏度：以1标准大气压下水的结冰点为0度，沸点为100度，中国等世界大多数国家使用； 华氏度：以1标准大气压下水的结冰点为32度，沸点为212度，英美等国家使用； 系，
1，输入：输入带华氏或摄氏标致的温度值，, 2，处理：根据温度标致选择适当的温度转换算法， 3,输出：输出带摄氏或华氏的温度值， <F标识华氏度，C表示摄氏度，
华氏转换公式：F=C*1.8 32 摄氏转换公式：C=(F-32)/1.8
代码语言：javascript复制#TempConvert.py
TempStr = input("请输入带有符号的温度值:")
if TempStr[-1] in ['F','f']:
C = (eval(TempStr[0:1])-32)/1.8
print('转换后的温度是{:.2f}C'.format(C))
elif TempStr[-1] in ['C','c']:
F = 1.8*eval(TempStr[0:1]) 32
print("转换后的温度是{:.2f}F".format(F))
else:
print("输入格式错误")温度转换问题是各类转换问题的代表性问题，如货币转换、长度转换、重量转换、面积转换等
实例二、天天向上的力量
问题1：千分之一的力量 -一年365天，每天进步千分之一，累计进步多少呢？ -一年365天，每天退步千分之一，累计剩下多少呢？
代码语言：javascript复制#DayDayUpQ1.py
dayup=pow(1.001,365)
daydown=pow(0.999,365)
print("向上:{:.2f},向下:{:.2f}".format(dayup,daydown))问题2：千分之五和白分之一的力量 -一年365天，每天进步千分之五或百分之一，累计退步多少呢？ -一年365天，每天退步千分之五或百分之一，累计退步多少呢？
代码语言：javascript复制#DayDayUpQ2.py
dayfactor=0.005
dayup=pow(1 dayfactor,365)
daydown=pow(1-dayfactor,365)
print("向上:{:.2f},向下:{:.2f}".format(dayup,daydown))#DayDayUpQ2.py
dayfactor=0.01
dayup=pow(1 dayfactor,365)
daydown=pow(1-dayfactor,365)
print("向上:{:.2f},向下:{:.2f}".format(dayup,daydown))问题3：工作日的力量 -一年365天，一周5个公作日，每天进步1% -一年365天，一周2个公作日，每天退步1% -这种工作日的力量，如何呢？
代码语言：javascript复制#DayDayUp3.py
dayup=1.0
dayfactor=0.01
for i in range(365):
if i % 7 in [6,0]:
dayup=dayup*(1-dayfactor)
else:
dayup=dayup*(1 dayfactor)
print("工作日的力量:{:.2f}".format(dayup))问题4：工作日的努力 -工作日模式要努力到什么水平，才能与每天努力1%一样？ 假设两个人 -A君：一年365天，每天进步1%，不停歇 -B君：一年365天，每周工作5天休息2天，休息日下降1%，要多努力呢？
代码语言：javascript复制#DayDayUpQ4.py
def dayUP(df):
dayup=1
for i in range(365):
if i % 7 in [6,0]:
dayup=dayup*(1-0.01)
else:
dayup=dayup*(1 df)
return dayup
dayfactor=0.01
while dayUP(dayfactor)<37.78:
dayfactor =0.001
print("工作日的努力参数是:{:.3f}".format(dayfactor))实例三、python蟒蛇的绘制
参考turtle库专题内容：python蟒蛇绘制
实例四、文本进度条
1、文本进度条 简单的开始
代码语言：javascript复制#TextProBarV1.py
import time
scale = 10
print("------执行开始------")
for i in range(scale 1):
a = '*' * i
b = '.' * (scale - i)
c = (i/scale)*100
print("{:^3.0f}%[{}->{}]".format(c,a,b))
time.sleep(0.1)
print("------执行结束------")2、文本进度条 单行动态刷新
代码语言：javascript复制#TextProBarV2.py
import time
for i in range(101):
print("r{:3}%".format(i), end="")
time.sleep(0.1)3、文本进度条 实例完整效果
代码语言：javascript复制#TextProBarV3.py
import time
scale = 50
print("执行开始".center(scale//2, "-"))
start = time.perf_counter()
for i in range(scale 1):
a = '*' * i
b = '.' * (scale - i)
c = (i/scale)*100
dur = time.perf_counter() - start
print("r{:^3.0f}%[{}->{}]{:.2f}s".format(c,a,b,dur),end='')
time.sleep(0.1)
print("n" "执行结束".center(scale//2,'-'))实例五、身体质量指数BMI
国际：
代码语言：javascript复制#CalBMIv1.py
height, weight = eval(input("请输入身高(米)和体重(公斤)[逗号隔开]: "))
bmi = weight / pow(height, 2)
print("BMI 数值为：{:.2f}".format(bmi))
who = ""
if bmi < 18.5:
who = "偏瘦"
elif 18.5 <= bmi < 25:
who = "正常"
elif 25 <= bmi < 30:
who = "偏胖"
else:
who = "肥胖"
print("BMI 指标为:国际'{0}'".format(who))国内：
代码语言：javascript复制#CalBMIv2.py
height, weight = eval(input("请输入身高(米)和体重(公斤)[逗号隔开]: "))
bmi = weight / pow(height, 2)
print("BMI 数值为：{:.2f}".format(bmi))
nat = ""
if bmi < 18.5:
nat = "偏瘦"
elif 18.5 <= bmi < 24:
nat = "正常"
elif 24 <= bmi < 28:
nat = "偏胖"
else:
nat = "肥胖"
print("BMI 指标为:国内'{0}'".format(nat))两个同时：
代码语言：javascript复制#CalBMIv3.py
height, weight = eval(input("请输入身高(米)和体重(公斤)[逗号隔开]: "))
bmi = weight / pow(height, 2)
print("BMI 数值为：{:.2f}".format(bmi))
who, nat = "", ""
if bmi < 18.5:
who, nat = "偏瘦", "偏瘦"
elif 18.5 <= bmi < 24:
who, nat = "正常", "正常"
elif 24 <= bmi < 25:
who, nat = "正常", "偏胖"
elif 25 <= bmi < 28:
who, nat = "偏胖", "偏胖"
elif 28 <= bmi < 30:
who, nat = "偏胖", "肥胖"
else:
who, nat = "肥胖", "肥胖"
print("BMI 指标为:国际'{0}', 国内'{1}'".format(who, nat))实例六、圆周率的计算
公式法
代码语言：javascript复制#CalPiV1.py
pi = 0
N = 100
for k in range(N):
pi = 1/pow(16,k)*(
4/(8*k 1) - 2/(8*k 4) -
1/(8*k 5) - 1/(8*k 6) )
print("圆周率值是: {}".format(pi))蒙特卡罗方法
代码语言：javascript复制#CalPiV2.py
from random import random
from time import perf_counter
DARTS = 1000*1000
hits = 0.0
start = perf_counter()
for i in range(1, DARTS 1):
x, y = random(), random()
dist = pow(x ** 2 y ** 2, 0.5)
if dist <= 1.0:
hits = hits 1
pi = 4 * (hits/DARTS)
print("圆周率值是: {}".format(pi))
print("运行时间是: {:.5f}s".format(perf_counter() - start))实例七、七段数码管绘制
版本一：
代码语言：javascript复制#SevenDigitsDrawV1.py
import turtle
def drawLine(draw): #绘制单段数码管
turtle.pendown() if draw else turtle.penup()
turtle.fd(40)
turtle.right(90)
def drawDigit(digit): #根据数字绘制七段数码管
drawLine(True) if digit in [2,3,4,5,6,8,9] else drawLine(False)
drawLine(True) if digit in [0,1,3,4,5,6,7,8,9] else drawLine(False)
drawLine(True) if digit in [0,2,3,5,6,8,9] else drawLine(False)
drawLine(True) if digit in [0,2,6,8] else drawLine(False)
turtle.left(90)
drawLine(True) if digit in [0,4,5,6,8,9] else drawLine(False)
drawLine(True) if digit in [0,2,3,5,6,7,8,9] else drawLine(False)
drawLine(True) if digit in [0,1,2,3,4,7,8,9] else drawLine(False)
turtle.left(180)
turtle.penup()
turtle.fd(20)
def drawDate(date): #获得要输出的数字
for i in date:
drawDigit(eval(i)) #通过eval()函数将数字变为整数
def main():
turtle.setup(800, 350, 200, 200)
turtle.penup()
turtle.fd(-300)
turtle.pensize(5)
drawDate('20181010')
turtle.hideturtle()
turtle.done()
main()版本二：
代码语言：javascript复制#SevenDigitsDrawV2.py
import turtle, time
def drawGap(): #绘制数码管间隔
turtle.penup()
turtle.fd(5)
def drawLine(draw): #绘制单段数码管
drawGap()
turtle.pendown() if draw else turtle.penup()
turtle.fd(40)
drawGap()
turtle.right(90)
def drawDigit(d): #根据数字绘制七段数码管
drawLine(True) if d in [2,3,4,5,6,8,9] else drawLine(False)
drawLine(True) if d in [0,1,3,4,5,6,7,8,9] else drawLine(False)
drawLine(True) if d in [0,2,3,5,6,8,9] else drawLine(False)
drawLine(True) if d in [0,2,6,8] else drawLine(False)
turtle.left(90)
drawLine(True) if d in [0,4,5,6,8,9] else drawLine(False)
drawLine(True) if d in [0,2,3,5,6,7,8,9] else drawLine(False)
drawLine(True) if d in [0,1,2,3,4,7,8,9] else drawLine(False)
turtle.left(180)
turtle.penup()
turtle.fd(20)
def drawDate(date):
turtle.pencolor("red")
for i in date:
if i == '-':
turtle.write('年',font=("Arial", 18, "normal"))
turtle.pencolor("green")
turtle.fd(40)
elif i == '=':
turtle.write('月',font=("Arial", 18, "normal"))
turtle.pencolor("blue")
turtle.fd(40)
elif i == ' ':
turtle.write('日',font=("Arial", 18, "normal"))
else:
drawDigit(eval(i))
def main():
turtle.setup(800, 350, 200, 200)
turtle.penup()
turtle.fd(-350)
turtle.pensize(5)
# drawDate('2018-10=10 ')
drawDate(time.strftime('%Y-%m=%d ',time.gmtime()))
turtle.hideturtle()
turtle.done()
main()实例八、科赫曲线绘制
代码语言：javascript复制#KochDrawV1.py
import turtle
def koch(size, n):
if n == 0:
turtle.fd(size)
else:
for angle in [0, 60, -120, 60]:
turtle.left(angle)
koch(size/3, n-1)
def main():
turtle.setup(800,400)
turtle.penup()
turtle.goto(-300, -50)
turtle.pendown()
turtle.pensize(2)
koch(600,3) # 0阶科赫曲线长度，阶数
turtle.hideturtle()
main()科赫雪花绘制
代码语言：javascript复制#KochDrawV2.py
import turtle
def koch(size, n):
if n == 0:
turtle.fd(size)
else:
for angle in [0, 60, -120, 60]:
turtle.left(angle)
koch(size/3, n-1)
def main():
turtle.setup(600,600)
turtle.penup()
turtle.goto(-200, 100)
turtle.pendown()
turtle.pensize(2)
level = 3 # 3阶科赫雪花，阶数
koch(400,level)
turtle.right(120)
koch(400,level)
turtle.right(120)
koch(400,level)
turtle.hideturtle()
main()实例九、基本统计值计算
代码语言：javascript复制#CalStatisticsV1.py
def getNum(): #获取用户不定长度的输入
nums = []
iNumStr = input("请输入数字(回车退出): ")
while iNumStr != "":
nums.append(eval(iNumStr))
iNumStr = input("请输入数字(回车退出): ")
return nums
def mean(numbers): #计算平均值
s = 0.0
for num in numbers:
s = s num
return s / len(numbers)
def dev(numbers, mean): #计算方差
sdev = 0.0
for num in numbers:
sdev = sdev (num - mean)**2
return pow(sdev / (len(numbers)-1), 0.5)
def median(numbers): #计算中位数
sorted(numbers)
size = len(numbers)
if size % 2 == 0:
med = (numbers[size//2-1] numbers[size//2])/2
else:
med = numbers[size//2]
return med
n = getNum() #主体函数
m = mean(n)
print("平均值:{},方差:{:.2},中位数:{}.".format(m, dev(n,m),median(n)))实例10、文本词频统计
Hamlet词频统计
代码语言：javascript复制#CalHamletV1.py
def getText():
txt = open("hamlet.txt", "r").read()
txt = txt.lower()
for ch in '!"#$%&()* ,-./:;<=>?@[\]^_‘{|}~':
txt = txt.replace(ch, " ") #将文本中特殊字符替换为空格
return txt
hamletTxt = getText()
words = hamletTxt.split()
counts = {}
for word in words:
counts[word] = counts.get(word,0) 1
items = list(counts.items())
items.sort(key=lambda x:x[1], reverse=True)
for i in range(10):
word, count = items[i]
print ("{0:<10}{1:>5}".format(word, count))三国演义》人物出场统计（上）（含《三国演义》原文文本）
代码语言：javascript复制#CalThreeKingdomsV1.py
import jieba
txt = open("threekingdoms.txt", "r", encoding='utf-8').read()
words = jieba.lcut(txt)
counts = {}
for word in words:
if len(word) == 1:
continue
else:
counts[word] = counts.get(word,0) 1
items = list(counts.items())
items.sort(key=lambda x:x[1], reverse=True)
for i in range(15):
word, count = items[i]
print ("{0:<10}{1:>5}".format(word, count))《三国演义》人物出场统计（下）（含《三国演义》原文文本）
代码语言：javascript复制#CalThreeKingdomsV2.py
import jieba
excludes = {"将军","却说","荆州","二人","不可","不能","如此"}
txt = open("threekingdoms.txt", "r", encoding='utf-8').read()
words = jieba.lcut(txt)
counts = {}
for word in words:
if len(word) == 1:
continue
elif word == "诸葛亮" or word == "孔明曰":
rword = "孔明"
elif word == "关公" or word == "云长":
rword = "关羽"
elif word == "玄德" or word == "玄德曰":
rword = "刘备"
elif word == "孟德" or word == "丞相":
rword = "曹操"
else:
rword = word
counts[rword] = counts.get(rword,0) 1
for word in excludes:
del counts[word]
items = list(counts.items())
items.sort(key=lambda x:x[1], reverse=True)
for i in range(10):
word, count = items[i]
print ("{0:<10}{1:>5}".format(word, count))
