控制#
介绍#
控件包括用于计时、程序流程、条件逻辑和项目终止的方法。这些控件允许您暂停执行、创建循环、定义逻辑路径以及结束程序。以下是可用控件的列表,包括方法和核心 Python 关键字:
wait
– Pauses execution for a given number of milliseconds or seconds.for
– Repeats code for each item in a sequence.if
– Executes code if a condition is true.if/else
– Runs different code depending on a condition.if/elif/else
– Checks multiple conditions in order.while
– Repeats code while a condition is true.break
– Exits a loop immediately.stop_program
– Ends the running program.pass
– Placeholder used when no action is needed.
等待#
wait
暂停特定时间后再转到下一个方法。
用法:wait(time, units)
参数 |
描述 |
---|---|
|
等待的时间量,以正整数表示。 |
|
毫秒 |
# Build Used: Super Code Base 2.0
def main():
# Turn right for one second
drivetrain.turn(RIGHT)
wait(1, SECONDS)
drivetrain.stop()
# Start threads — Do not delete
start_thread(main)
为了#
for
遍历一个序列(例如列表、元组、字典、集合或字符串)或任何可迭代对象。它对序列中的每个项目执行一次代码块。
使用量:
for value in expression_list:
pass
参数 |
描述 |
---|---|
|
存储迭代中的当前元素的临时变量。 |
|
循环遍历的元素集合(例如,列表、字符串、范围)。 |
# Build Used: Super Code Base 2.0
def main():
# Move in a square path
for index in range(4):
drivetrain.drive_for(FORWARD, 100, MM)
drivetrain.turn_for(RIGHT, 90)
# Start threads — Do not delete
start_thread(main)
如果#
if
如果条件评估为 True
则执行缩进的代码块。
用法:
if condition:
pass
参数 |
描述 |
---|---|
|
语句运行时要求值的表达式或变量。如果求值为 |
# Build Used: Super Code Base 2.0
def main():
# Turn when the bumper is pressed
while True:
if bumper.is_pressed():
drivetrain.turn_for(RIGHT, 90)
wait(0.1, SECONDS)
# Start threads — Do not delete
start_thread(main)
如果/否则#
if
and else
根据条件评估结果为 True
或 False
确定运行哪个缩进的代码块。
用法:
if condition:
pass
else:
pass
参数 |
描述 |
---|---|
|
语句运行时求值的表达式或变量。如果求值为 |
# Build Used: Super Code Base 2.0
def main():
# Turn when the bumper is pressed
while True:
if bumper.is_pressed():
drivetrain.turn(RIGHT)
else:
drivetrain.stop()
wait(0.1, SECONDS)
# Start threads — Do not delete
start_thread(main)
如果/否则#
if/elif/else
结构根据条件选择运行哪个缩进的代码块:
if
如果条件评估为True
则运行其块。elif
仅当所有先前条件的评估结果为False
时才检查附加条件。可以使用多个elif
语句。else
仅当先前的条件都不为True
时才运行其块。
用法:
if condition:
pass
elif condition:
pass
else:
pass
参数 |
描述 |
---|---|
|
语句运行时求值的表达式或变量。第一个求值为 |
# Build Used: Super Code Base 2.0
def main():
# Change the LED while turning
drivetrain.turn(RIGHT)
while True:
if drivetrain.get_heading() < 120:
bumper.set_color(OFF)
elif drivetrain.get_heading() < 240:
bumper.set_color(RED)
else:
bumper.set_color(GREEN)
wait(0.2, SECONDS)
# Start threads — Do not delete
start_thread(main)
尽管#
while
只要条件为 True
就会重复运行方法。它也可以像“等待直到”一样使用,只需在条件中添加 not
,如下例所示。
用法:
while condition:
pass
参数 |
描述 |
---|---|
|
每次迭代前都会求值的表达式或变量。如果求值为 |
# Build Used: Super Code Base 2.0
def main():
# Turn when the bumper is pressed
while True:
if bumper.is_pressed():
drivetrain.turn(RIGHT)
else:
drivetrain.stop()
wait(0.1, SECONDS)
# Start threads — Do not delete
start_thread(main)
# Build Used: Super Code Base 2.0
def main():
# Turn the other direction when the bumper is pressed
drivetrain.turn(LEFT)
while not bumper.is_pressed():
wait(0.2, SECONDS)
drivetrain.turn(RIGHT)
# Start threads — Do not delete
start_thread(main)
休息#
break
立即退出循环。
# Build Used: Super Code Base 2.0
def main():
# Stop turning after pressing the bumper
while True:
drivetrain.turn(RIGHT)
if bumper.is_pressed():
break
wait(0.2, SECONDS)
drivetrain.stop()
bumper.set_color(RED)
# Start threads — Do not delete
start_thread(main)
停止程序#
program_stop
结束正在运行的项目。
用法:brain.program_stop()
参数 |
描述 |
---|---|
该方法没有参数。 |
# Build Used: Super Code Base 2.0
def main():
# Stop the project after pressing the bumper
while True:
drivetrain.turn(RIGHT)
if bumper.is_pressed():
break
wait(0.2, SECONDS)
stop_program()
# Start threads — Do not delete
start_thread(main)
经过#
pass
是未来代码的占位符,可用于避免空循环、条件和函数中的错误。
if condition:
pass
def function():
pass