函数

函数是一段代码的表示
def <函数名>(<参数(0个或多个)>):#（）必须有
      <函数体>
      <返回值>
参数（<非可选参数>,<可选参数>）#可选在后面
def fac(n,m=2):
    sum =1
    for i in range(1,n+1):
        sum*=i
    return sum//m
print(fac(5)) 60
print(fac(5,3)) 40 #1.位置传递，2.fac(m==3,n==5)名称传递 参数传递的2种方式
def fac(n,*m):# *m 为可变参数，数量不确定
    sum =1
    for i in range(1,n+1):
        sum*=i
    for j in m:
        sum*=j
        print(j,sum)
    return sum
fac(5,3,2,6)
3 360
2 720
6 4320

函数可以没有返回值，return 用来传递返回值, 可以没有return .
return 可以传递0个返回值，也可以传递任意多个返回值
>>> def fac(n,m=2):
    sum =1
    for i in range(1,n+1):
        sum*=i
    return sum//m,n,m
>>> fac(10,5)
(725760, 10, 5)
a,b,c = fac(10,5)
print(a,b,c)
725760 10 5

n,s = 10,100 #n,s 为全局变量
def fac(n):
    s =1  #fac()函数里的n,s为局部变量
    for i in range(1,n+1):
        s*=i
    return s
print(fac(n),s) #n,s 为全局变量
3628800 100


函数运算结束后，局部变量被释放
可以使用global 保留字在函数内部使用全局变量
n,s = 10,100
def fac(n):
    global s #s 为全局变量
    for i in range(1,n+1):
        s*=i
    return s
print(fac(n),s)
362880000 362880000

局部变量为组合数据类型且未创建，等同于全局变量
ls = ['d','w']
def f(a):
    ls.append(a)
    return
f('g')
print(ls)
['d', 'w', 'g']

ls = ['s','e']
def f(a):
ls=[]
ls.append(a)
print(ls)
f('v')
print(ls)

['v']
['s', 'e']

7星管绘制时间

import turtle,time
def drawgap():
    turtle.pu()
    turtle.fd(5)
def drawline(draw):
    drawgap()
    turtle.pd() if draw else turtle.pu()
    turtle.fd(40)
    drawgap()
    turtle.rt(90)
def drawdigit(digit):
    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.lt(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 [0,1,2,3,4,5,7,8,9] else drawline(False)
    turtle.lt(180)
    turtle.pu()
    turtle.fd(10)
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.pu()
    turtle.fd(-300)
    turtle.pensize(5)
    drawdate(time.strftime('%Y-%m=%d+',time.gmtime()))
    turtle.hideturtle()
    turtle.done()
main()

#判断素数
def prime(m):
    if m < 2:
        return False#首字母大写
    else:
        end = int(pow(m, 0.5) + 1)
        for i in range(2, end):
            if m%i == 0:
                return False
        else:
            return True

#连续乘法
'''
def cmul(s):
    sum =1
    for i in s:
        if i!=',':
            sum*=int(i)
    return sum
s = input()
sum = cmul(s)
print(sum)
'''
def cmul(a, *b):
    m = a
    for i in b:
        m *= i
    return m
print(eval("cmul({})".format(input())))
1,2,3,4,5
120

def dayup(df):
    daup = 1
    for i in range(365):
        if i%7 in [0,6]:
            daup = daup*(1-0.01)
        else:
            daup = daup*(1+df)
    return daup#空格一定要合适
daf = 0.01
while dayup(daf) < 37.78:
       daf+=0.001
print("{:.3f}".format(daf))