Python入门学习笔记二

最近由于膝盖半月板撕裂做了手术，在家没事干，趁机学习下python基础语法~~

1.程序的控制结构

实例：BMI计算

#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,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:国外{0}，国内{1}".format(who,nat))

2.程序的循环结构

实例：计算圆周率

#CalPiV2.py
import random
import time
DARTS=1000*1000
hits=0.0
start=time.perf_counter()
for i in range(1,DARTS+1):
    x,y=random.random(),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}".format(time.perf_counter()-start))

计算水仙花数

s=""
for i in range(100,1000):
    t=str(i)
    if pow(eval(t[0]),3)+pow(eval(t[1]),3)+pow(eval(t[2]),3)==i:
        s+="{},".format(i)
print(s[:-1]) 

3.函数和代码复用

实例：七段数码管

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(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()  #为绘制后续数字确定位置
    turtle.fd(20)   #为绘制后续数字确定位置
def drawData(data):  #获取要输出的数字  data为日期，格式为‘%Y-%m=&d+’
    turtle.pencolor("red")
    for i in data:
        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))  #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)
    drawData("2022-3=18+")  #drawData(time.strftime("%Y-%m=%d+",time.gmtime()))
    turtle.hideturtle()
    turtle.done()
main()

实例：科赫雪花绘制

#KochDrawV1.py  函数递归实例
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阶科赫曲线，阶数
    koch(400,level)
    turtle.right(120)
    koch(400,level)
    turtle.right(120)
    koch(400,level)
    turtle.hideturtle()
main()