在实现玩转小迷宫这个游戏时，分别使用了input()输入函数、print()输出函数、if…elif…else语句、二维列表、while循环、for循环
下面对这些用法再一次重温
1.input()输入函数
在 Python 中，使用内置函数 input() 可以接收用户的键盘输入。input() 函数的基本用法如下：
variable = input("提示文字")
其中，variable 为保存输入结果的变量，双引号内的文字用于提示要输入的内容。例如，想要接收 用户输入的内容，并保存到变量tip中，可以使用下面的代码：
tip = input("请输入文字：")
在ython3.x中，无论输入的是数字还是字符都将被作为字符串读取。如果想要接收数值，需要把接收到的字符串进行类型转换。例如，想要接收整型的数字并保存到变量age中，可以使用下面的代码：
age = int(input("请输入数字："))
说明：在Python2.x中，input()函数接收内容时，数值直接输入即可，并且接收后的内容作为数字类型；而如果要输入字符串类型的内容，需要将对应的字符串使用引号括起来，否则会报错。
实现根据身高、体重计算BMI指数的示例代码如下：
height = float(input("请输入您的身高（单位为米）：")) # 输入身高，单位：米
weight = float(input("请输入您的体重（单位为千克)：")) # 输入体重，单位：千克
bmi=weight/(height*height) # 用于计算BMI指数，公式为“体重/身高的平方”
print("您的BMI指数为："+str(bmi)) # 输出BMI指数
# 判断身材是否合理
if bmi<18.5:
print("您的体重过轻 ~@_@~")
if bmi>=18.5 and bmi<24.9:
print("正常范围，注意保持 (-_-)")
if bmi>=24.9 and bmi<29.9:
print("您的体重过重 ~@_@~")
if bmi>=29.9:
print("肥胖 ^@_@^")
2.print()输出函数
默认的情况下，在Python中，使用内置的print()函数可以将结果输出到IDLE或者标准控制台上。其基本语法格式如下：
print(输出内容)
中，输出内容可以是数字和字符串（字符串需要使用引号括起来），此类内容将直接输出，也可以是包含运算符的表达式，此类内容将计算结果输出。例如：
a = 10 # 变量a，值为10
b = 6 # 变量b，值为6
print(6) # 输出数字6
print(a*b) # 输出变量a*b的结果60
print(a if a>b else b) # 输出条件表达式的结果10
print("成功的唯一秘诀——坚持最后一分钟") # 输出字符串“成功的唯一秘诀——坚持最后一分钟”
3.if…elif…else语句
在开发程序时，如果遇到多选一的情况，则可以使用if…elif…else语句，该语句是一个多分支选择语句，通常表现为“如果满足某种条件，就会进行某种处理，否则，如果满足另一种条件，则执行另一种处理……”。if…elif…else语句的语法格式如下：
if 表达式1: 语句块1
elif 表达式2: 语句块2
elif 表达式3: 语句块3
…
else:语句块n
使用if…elif…else语句时，表达式可以是一个单纯的布尔值或变量，也可以是比较表达式或逻辑表达式，如果表达式为真，执行语句；而如果表达式为假，则跳过该语句，进行下一个elif的判断，只有在所有表达式都为假的情况下，才会执行else中的语句。
注意：if和elif都需要判断表达式的真假，而else则不需要判断；另外，elif和else都必须跟if一起使用，不能单独使用。
使用if…elif…else多分支语句实现根据用户输入的年龄输出相应的提示信息的功能，示例代码如下：
your_age = int(input("请输入您的年龄：")) # 获取用户输入的年龄，并转换为整型
if your_age <= 18: # 调用if语句判断输入的数据是否小于等于18
# 如果小于等于18则输出提示信息
print("您的年龄还小，要努力学习哦！")
elif 18 < your_age <= 30: # 判断是否大于18岁，并且小于30岁
# 如果输入的年龄大于18岁并且小于30岁则输出提示信息
print("您现在的阶段正是努力奋斗的黄金阶段！")
elif 30 < your_age <= 50: # 判断输入的年龄是否大于30岁小于等于50岁
# 如果输入的年龄大于30岁而小于等于50岁则输出提示信息
print("您现在的阶段正是人生的黄金阶段！")
else:
print("最美不过夕阳红！")
说明：第1行代码中的int()函数用于将用户的输入强制转换成整型。
4.二维列表
在Python中，由于列表元素还可以是列表，所以它也支持二维列表的概念。那么什么是二维列表？前文提到酒店有很多房间，这些房间都可以构成一个列表，如果这个酒店有500个房间，那么拿到499号房钥匙的旅客可能就不高兴了，从1号房走到499号房要花好长时间，因此酒店设置了很多楼层，每一个楼层都会有很多房间，形成一个立体的结构，把大量的房间均摊到每个楼层，这种结构就是二维列表结构。使用二维列表结构表示酒店每个楼层的房间号的效果
在Python中，二维列表是包含列表的列表，即一个列表的每一个元素又都是一个列表。创建二维列表可以参考以下代码：
listname = [['千', '山', '鸟', '飞', '绝'],
['万', '径', '人', '踪', '灭'],
['孤', '舟', '蓑', '笠', '翁'],
['独', '钓', '寒', '江', '雪']]
创建二维数组后，可以通过以下语法格式访问列表中的元素：
listname[下标1][下标2]
参数说明如下：
- listname ：列表名称。
- 下标 1 ：表示列表中第几行，下标值从 0 开始，即第一行的下标为 0。
- 下标 2 ：表示列表中第几列，下标值从 0 开始，即第一列的下标为 0。 例如，要访问二维列表中的第 2 行，第 4
列，可以使用下面的代码：
print(listname[1][3])
5.while循环
while循环是通过一个条件来控制是否要继续反复执行循环体中的语句。语法如下：
while 条件表达式:
循环体
说明：循环体是指一组被重复执行的语句。
当条件表达式的返回值为真时，则执行循环体中的语句，执行完毕后，重新判断条件表达式的返 回值，直到表达式返回的结果为假时，退出循环。while 循环语句的执行流程
使用while循环语句实现从1开始依次尝试符合条件的数，直到找到符合条件的数时，才退出循环。具体的实现方法是：首先定义一个用于计数的变量number和一个作为循环条件的变量none（默认值为真），然后编写while循环语句，在循环体中，将变量number的值加1，并且判断number的值是否符合条件，当符合条件时，将变量none设置为假，从而退出循环。具体代码如下：
print("今有物不知其数，三三数之剩二，五五数之剩三，七七数之剩二，问几何？\n")
none = True # 作为循环条件的变量
number = 0 # 计数的变量
while none:
number += 1 # 计数加1
if number%3 ==2 and number%5 ==3 and number%7 ==2: # 判断是否符合条件
print("答曰：这个数是",number) # 输出符合条件的数
none = False # 将循环条件的变量赋值为否
6.for循环
for循环是一个依次重复执行的循环。通常适用于枚举或遍历序列，以及迭代对象中的元素。语法如下：
for 迭代变量 in 对象:
循环体
其中，迭代变量用于保存读取出的值；对象为要遍历或迭代的对象，该对象可以是任何有序的序列对象，如字符串、列表和元组等；循环体为一组被重复执行的语句。
for循环语句的执行流程
在使用 for 循环时，最基本的应用就是进行数值循环。例如，想要实现从 1 到 100 的累加，可以 通过下面的代码实现：
print("计算1+2+3+……+100的结果为：")
result = 0 # 保存累加结果的变量
for i in range(101):
result += i # 实现累加功能
print(result) # 在循环结束时输出结果
上面的代码中，使用了range()函数，该函数是Python内置的函数，用于生成一系列连续的整数，多用于for循环语句中。其语法格式如下：
range(start,end,step)
参数说明如下：
- start ：用于指定计数的起始值，可以省略，如果省略则从 0 开始。
- end ：用于指定计数的结束值（但不包括该值，如 range(7)，则得到的值为 0~6，不包括 7）， 不能省略。当 range()
函数中只有一个参数时，即表示指定计数的结束值。 - step ：用于指定步长，即两个数之间的间隔，可以省略，如果省略则表示步长为 1。例如， range(1,7) 将得到
1、2、3、4、5、6。
注意：在使用range()函数时，如果只有一个参数，那么表示指定的是end；如果有两个参数，则表3
示指定的是start和end；如果3个参数都存在时，最后一个参数才表示步长。
实例
import time # 导入时间模块
# 模拟迷宫地图的二维列表
map_list=[
[" ","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@"],
["=>","Y"," "," ","@","@"," "," "," "," "," "," ","@"," "," "," ","@","@"," "," "," ","@"," ","@"," ","@"," ","@"," ","@","@"],
[" ","@"," "," ","@","@","@"," ","@"," ","@"," ","@","@","@"," "," "," "," ","@"," ","@"," ","@","@","@"," ","@","@","@","@"],
[" ","@"," ","@"," "," "," ","@","@"," ","@"," "," "," ","@","@","@","@","@","@"," ","@"," ","@","@","@"," "," "," ","@","@"],
[" ","@"," "," "," ","@"," ","@","@"," "," ","@","@","@"," ","@","@"," ","@"," "," ","@"," "," ","@","@"," ","@","@","@","@"],
[" ","@","@","@","@","@"," ","@"," ","@","@"," "," ","@"," ","@","@","@","@","@"," ","@","@"," "," "," "," ","@","@","@","@"],
[" ","@"," "," "," ","@"," ","@","@","@","@","@"," ","@"," "," "," ","@","@","@"," ","@"," ","@"," ","@"," "," "," "," ","@"],
[" ","@"," ","@"," ","@"," ","@","@"," ","@","@","@"," "," ","@","@"," "," "," "," ","@","@","@"," ","@"," ","@","@","@","@"],
[" ","@"," ","@"," "," "," ","@","@"," "," "," ","@","@","@","@","@","@","@","@","@","@","@"," ","@","@","@"," "," "," ","@"],
[" ","@"," ","@","@","@","@","@","@"," ","@"," ","@","@","@","@","@"," "," "," "," "," "," "," "," "," "," "," ","@"," ","@"],
[" ","@"," "," "," "," "," "," "," "," ","@"," ","@"," "," "," "," "," ","@","@","@","@","@"," ","@","@","@"," ","@"," "," ","=>"],
[" ","@"," ","@","@","@","@","@","@","@","@"," ","@","@","@","@","@"," ","@","@","@","@","@"," ","@","@","@"," ","@","@","@"],
[" ","@"," "," "," "," "," ","@"," ","@","@"," ","@","@","@","@","@"," ","@","@","@"," "," "," "," "," "," "," ","@","@","@"],
[" ","@","@","@","@","@"," ","@"," ","@","@"," ","@"," "," "," "," "," "," ","@","@","@","@","@","@","@","@"," ","@"," ","@"],
[" ","@"," "," "," "," "," ","@"," ","@","@"," ","@","@"," ","@","@","@"," "," "," "," "," "," "," "," ","@"," "," "," ","@"],
[" ","@"," ","@"," ","@","@","@"," "," "," "," "," "," "," ","@","@","@","@","@","@"," ","@","@","@","@","@","@","@"," ","@"],
[" ","@"," "," "," "," "," "," "," ","@","@"," ","@","@"," "," "," "," "," "," ","@"," "," "," "," "," "," "," "," "," ","@"],
[" ","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@","@"]]
# 更新地图
def up_map():
# 打印小标题并指定打印区域的文字以及背景颜色
print("\033[1;30;42m ----------小迷宫-----------")
for i,values in enumerate(map_list): # 遍历二维列表中的18个子列表
for j in range(len(values)): # 遍历子列表中的元素
# 打印每个子列表中的所有元素，并且不换行打印
print(map_list[i][j], end="")
print("") # 每打印一个子列表所有元素，换行一次
print("\033[0m",end="") # 背景色结束位置
if __name__ == '__main__':
x = 1 # 横向坐标默认值
y = 1 # 纵向坐标默认值
step_number = 0 # 记录行走步数的变量
up_map() # 更新模拟地图
start = time.time() # 获取开始时的时间戳
while True:
# 判断当小人走到迷宫出口时，打印胜利文字，跳出循环
if x == 30 and y == 10:
print("\033[31m恭喜您！走出了迷宫！\033[0m")
print("\033[31m共计行走了",step_number,"步！\033[0m")
print("\033[31m共计用时",int(time.time()-start),"秒！\033[0m")
break
print("\033[31m请输入行走的方向(输入exit将退出游戏！)\033[0m")
# 获取输入的行走方向w为上、s为下、a为左、d为右
direction = input("\033[31mw为上、s为下、a为左、d为右：\033[0m")
# 当用户输入w，控制人物向上走
if (direction == "w"):
if map_list[y - 1][x] != "@":
map_list[y][x] = " "
y -= 1
map_list[y][x] = "Y"
step_number += 1 # 修改小人移动步数
else:
print('\033[31m碰到墙壁！\033[0m')
up_map() # 更新地图
# 当用户输入s，控制人物向下走
elif (direction == "s"):
if map_list[y+1][x] != "@": # 判断行走位置不是墙时，@（表示墙）
map_list[y][x] = " " # 将小人原来的位置设置为空
y += 1 # 修改Y坐标位置
map_list[y][x] = "Y" # 将移动后的位置设置为Y（表示小人）
step_number+=1 # 修改小人移动步数
else:
print('\033[31m碰到墙壁！\033[0m') # 当用户输入的位置是墙时，做出提示
up_map() # 更新地图
# 当用户输入a，控制人物向左走
elif (direction == "a"):
if map_list[y][x - 1] != "@":
map_list[y][x] = " "
x -= 1
map_list[y][x] = "Y"
step_number += 1 # 修改小人移动步数
else:
print('\033[31m碰到墙壁！\033[0m')
up_map() # 更新地图
# 当用户输入d，控制人物向右走
elif (direction == "d"):
if map_list[y][x + 1] != "@":
map_list[y][x] = " "
x += 1
map_list[y][x] = "Y"
step_number += 1 # 修改小人移动步数
else:
print('\033[31m碰到墙壁！\033[0m')
up_map() #更新地图
# 当用户输入退出命令，跳出循环
elif (direction == "exit"):
print("游戏退出。")
break