【Python】第一个Python程序

1.Python实现Hello World

（1）编写代码

print('hello, world!')

（2）保存为hello.py文件

（3）运行程序

2.练习

（1）翻译以下程序运行后的结果
import this

（2）使用turtle绘制图形

import turtle

turtle.pensize(4)
turtle.pencolor('red')

turtle.forward(100)
turtle.right(90)
turtle.forward(100)
turtle.right(90)
turtle.forward(100)
turtle.right(90)
turtle.forward(100)

turtle.mainloop()

保存为flag.py，然后执行

（3）使用tutle画小猪佩奇

点击查看代码：tutle绘制小猪佩奇

"""
绘制小猪佩奇
"""
from turtle import *


def nose(x,y):
    """画鼻子"""
    penup()
    # 将海龟移动到指定的坐标
    goto(x,y)
    pendown()
    # 设置海龟的方向（0-东、90-北、180-西、270-南）
    setheading(-30)
    begin_fill()
    a = 0.4
    for i in range(120):
        if 0 <= i < 30 or 60 <= i <90:
            a = a + 0.08
            # 向左转3度
            left(3)
            # 向前走
            forward(a)
        else:
            a = a - 0.08
            left(3)
            forward(a)
    end_fill()
    penup()
    setheading(90)
    forward(25)
    setheading(0)
    forward(10)
    pendown()
    # 设置画笔的颜色(红, 绿, 蓝)
    pencolor(255, 155, 192)
    setheading(10)
    begin_fill()
    circle(5)
    color(160, 82, 45)
    end_fill()
    penup()
    setheading(0)
    forward(20)
    pendown()
    pencolor(255, 155, 192)
    setheading(10)
    begin_fill()
    circle(5)
    color(160, 82, 45)
    end_fill()


def head(x, y):
    """画头"""
    color((255, 155, 192), "pink")
    penup()
    goto(x,y)
    setheading(0)
    pendown()
    begin_fill()
    setheading(180)
    circle(300, -30)
    circle(100, -60)
    circle(80, -100)
    circle(150, -20)
    circle(60, -95)
    setheading(161)
    circle(-300, 15)
    penup()
    goto(-100, 100)
    pendown()
    setheading(-30)
    a = 0.4
    for i in range(60):
        if 0<= i < 30 or 60 <= i < 90:
            a = a + 0.08
            lt(3) #向左转3度
            fd(a) #向前走a的步长
        else:
            a = a - 0.08
            lt(3)
            fd(a)
    end_fill()


def ears(x,y):
    """画耳朵"""
    color((255, 155, 192), "pink")
    penup()
    goto(x, y)
    pendown()
    begin_fill()
    setheading(100)
    circle(-50, 50)
    circle(-10, 120)
    circle(-50, 54)
    end_fill()
    penup()
    setheading(90)
    forward(-12)
    setheading(0)
    forward(30)
    pendown()
    begin_fill()
    setheading(100)
    circle(-50, 50)
    circle(-10, 120)
    circle(-50, 56)
    end_fill()


def eyes(x,y):
    """画眼睛"""
    color((255, 155, 192), "white")
    penup()
    setheading(90)
    forward(-20)
    setheading(0)
    forward(-95)
    pendown()
    begin_fill()
    circle(15)
    end_fill()
    color("black")
    penup()
    setheading(90)
    forward(12)
    setheading(0)
    forward(-3)
    pendown()
    begin_fill()
    circle(3)
    end_fill()
    color((255, 155, 192), "white")
    penup()
    seth(90)
    forward(-25)
    seth(0)
    forward(40)
    pendown()
    begin_fill()
    circle(15)
    end_fill()
    color("black")
    penup()
    setheading(90)
    forward(12)
    setheading(0)
    forward(-3)
    pendown()
    begin_fill()
    circle(3)
    end_fill()


def cheek(x,y):
    """画脸颊"""
    color((255, 155, 192))
    penup()
    goto(x,y)
    pendown()
    setheading(0)
    begin_fill()
    circle(30)
    end_fill()


def mouth(x,y):
    """画嘴巴"""
    color(239, 69, 19)
    penup()
    goto(x, y)
    pendown()
    setheading(-80)
    circle(30, 40)
    circle(40, 80)


def setting():
    """设置参数"""
    pensize(4)
    # 隐藏海龟
    hideturtle()
    colormode(255)
    color((255, 155, 192), "pink")
    setup(840, 500)
    speed(10)


def main():
    """主函数"""
    setting() 
    nose(-100, 100)
    head(-69, 167)
    ears(0, 160)
    eyes(0, 140)
    cheek(80, 10)
    mouth(-20, 30)
    done()


if __name__ == '__main__':
    main()

3.开发工具选择

（1）IDLE
Python自带的，下载Python后可在开始菜单中找到

（2）iPython
基于Python的交互式解释器，打开命令行输入以下命令安装

pip install ipython

（3）Sublime Text
高级文本编辑器，官网：https://www.sublimetext.com/

（4）PyCharm
专门为Python开发者准备的，官网：https://www.jetbrains.com/pycharm/