功能#
介绍#
函数是 Python 编程的基本组成部分,它将代码片段打包成可复用、高效的代码段,用于执行特定任务。函数可以在程序中多次调用,从而简化代码组织,并有助于避免重复代码。函数还能使代码更易于调试。
Important: Defining a function alone doesn’t make it run. Use start_thread
to start running a function right when your project begins, instead of waiting for an event or callback.
def
定义一个函数。return
将函数的输出发送回主程序。
用法:
def function_name(parameters):
# Code to execute when the function is called
return result # Optional, used to return a value
参数 |
描述 |
---|---|
|
您为您的函数指定的名称。 |
|
可选。在调用函数时接受输入值的变量,允许将数据传递到函数中。 |
|
可选。让函数将结果返回给调用者。如果函数不包含 return 语句,则默认返回 |
注意:函数必须始终在*调用之前定义。
定义和调用函数#
Functions with No Parameters#
如果函数不需要输入,则可以定义不带参数的函数。
def greeting():
console.print("Hello!")
def main():
# Call the greeting function
greeting()
# Start threads — Do not delete
start_thread(main)
Functions with Parameters#
您还可以向函数添加参数,以便传递函数运行所需的信息。
# Build Used: Super Code Base 2.0
def move_square(moves):
for index in range(moves):
drivetrain.drive_for(FORWARD, 150)
drivetrain.turn_for(RIGHT, 90)
def main():
# Call the move_square function
move_square(4)
# Start threads — Do not delete
start_thread(main)
Functions with Default Arguments#
默认参数是如果函数调用中没有为该参数提供值,则采用默认值的参数。
# Build Used: Super Code Base 2.0
def move_square(moves=4):
for index in range(moves):
drivetrain.drive_for(FORWARD, 150)
drivetrain.turn_for(RIGHT, 90)
def main():
# Call the move_square function
move_square()
# Start threads — Do not delete
start_thread(main)
Return Values from Functions#
函数可以使用 return
关键字将数据发送回调用者。这允许您在程序中捕获并使用输出。
def times_two(number):
return number * 2
def main():
# Display the return value
console.print(times_two(2))
# Start threads — Do not delete
start_thread(main)
启动线程#
start_thread
调用一个函数,因此它在项目开始时立即开始运行。
如果使用多个 start_thread
,则这些功能将同时发生。
用法:
start_thread(function)
范围 |
描述 |
---|---|
|
先前定义的函数的名称。 |
# Build Used: Super Code Base 2.0
def move_square():
# Move in a square path
while True:
drivetrain.drive_for(FORWARD, 150)
drivetrain.turn_for(RIGHT, 90)
def led_lights():
# Blink LED lights
while True:
bumper.set_color(GREEN)
wait(0.5, SECONDS)
bumper.set_color(RED)
wait(0.5, SECONDS)
# Start threads — Do not delete
start_thread(move_square)
start_thread(led_lights)