Python函数01

Posted 2021-06-10 xingweikun

文章目录

• 函数的定义
• lambda函数
• 函数的参数传递
• • 可选参数和可变数量参数
  • 参数的位置和名称传递
  • 函数的返回值
• datetime 库
• 实例 七段数码管绘制

函数的定义

def happy():
    print("Happy birthday to you!")
def happyB(name):
    happy()
    happy()
    print("Happy birthday,dear {}!".format(name))
    happy()
happyB("Mike")
print()
happyB("Lily")

Happy birthday to you!
Happy birthday to you!
Happy birthday,dear Mike!
Happy birthday to you!

Happy birthday to you!
Happy birthday to you!
Happy birthday,dear Lily!
Happy birthday to you!

lambda函数

f=lambda x,y:x+y
print(type(f))
print(f(10,12))

<class 'function'>
22

函数的参数传递

可选参数和可变数量参数

def dup(str,times=2):
    print(str*times)
dup("knock~")

knock~knock~

def dup(str,times=2):
    print(str*times)
dup("knock~",4)

knock~knock~knock~knock~

def vfunc(a,*b):
    print(type(b))
    for n in b:
        a+=n
    return a
vfunc(1,2,3,4,5)

<class 'tuple'>
15

参数的位置和名称传递

func(x1,y1,z1,x2,y2,z2):
    return
result=func(1,2,3,4,5,6)

相当于

result=func(x2=4,y2=5,z2=6,x1=1,y1=2,z1=3)

函数的返回值

def func(a,b):
    return a*b
s=func("knock~",2)
print(s)

knock~knock~

def func(a,b):
    return b,a
s=func("knock~",2)
print(s,type(s))

(2, 'knock~') <class 'tuple'>
​

datetime 库

获得当前日期和时间对象

from datetime import datetime
datetime.now()

datetime.datetime(2021, 5, 15, 17, 34, 13, 282483)

获得当前日期和时间对应的UTC

datetime.utcnow()

datetime.datetime(2021, 5, 15, 9, 40, 48, 840603)

采用ISO 8601标准显示时间

today=datetime.now()
today.isoformat()

'2021-05-15T17:44:55.106858'

返回今天是星期几

today.isoweekday()

6

strftime()方法格式化

today.strftime("%Y-%m-%d %H:%M:%S")

'2021-05-15 17:44:55'

now=datetime.now()
print("今天是{0:%Y}年{0:%m}月{0:%d}日{0:%H}时{0:%M}分".format(now))

今天是2021年05月15日18时00分

实例 七段数码管绘制

import turtle
import datetime
def drawGap():
    turtle.penup()
    turtle.fd(5)
def drawLine(draw):
    drawGap()
    turtle.pendown() if draw else turtle.penup()
    turtle.fd(40)
    drawGap()
    turtle.right(90)
def drawDigit(d):
    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(-300)
    turtle.pensize(5)
    drawDate(datetime.datetime.now().strftime('%Y-%m=%d+'))
    turtle.hideturtle()
main()