save project

1.py

+"""
+print("hello world!")
+#输入 食物名称
+#input_food = input("今晚要吃什么：")
+#输出 要吃的食物
+#print("今晚我要吃_",input_food)
+
+#整型变量
+connter = 100
+#浮点型变量
+miles = 100.0
+#字符串型变量
+name = "bellcode"
+#查看变量类型
+print(type(connter))
+print(type(miles))
+print(type(name))
+
+#连续赋值相同的值
+a = b = c = 1
+print(a)
+print(b)
+print(c)
+
+#连续赋值相同的值
+a,b,c = 1,2,3
+print(a)
+print(b)
+print(c)
+
+
+#算数运算符
+x = 21
+y = 8
+#加运算
+print("x+y=",x+y)
+#减运算
+print("x-y=",x-y)
+#乘运算
+print("x*y=",x*y)
+#除运算
+print("x/y=",x/y)
+#取整除运算
+print("x//y=",x//y)
+#取余运算
+print("x%y=",x%y)
+#幂次方运算
+print("x**y=",x**y)
+
+
+
+width = int(input("三角形的底："))
+height = int(input("三角形的高："))
+print(type(width))
+print(type(height))
+
+print("三角形的面积为：",width*height/2)
+
+
+#int(x)将x转换为一个整数
+x = 2.7
+#向下取整
+print(int(x))
+
+x = "2"
+print(int(x))
+
+#将x装换为一个浮点数
+x = 2
+print(float(x))
+
+x = "9"
+print(float(x))
+
+
+#complex(x,y)
+x = 2
+y = 3
+print(complex(x))
+print(complex(y))
+
+
+x = 21
+#查看x的类型
+print("第一次查看：",type(x))
+#将整型装换成浮点型
+x = float(x)
+print("第二次查看：",type(x))
+
+
+x = 21
+y = 8
+z = complex(x,y)
+print(z)
+print(type(z))
+
+
+str1 = 'hahaha'
+str2 = "lalala"
+str3 = '''aaa'''
+print(str1,str2,str3)
+
+
+string = "Hello world!"
+#         01234567891011
+#  -12-11-10-9-8-7-6-5-4-3-2-1
+print("string[0]=",string[0])
+print("string[-1]=",string[-1])
+print("string[1:8]=",string[1:8])    #[1,8]  前闭后开
+print("string[1:-3]=",string[1:-3])  #[1,-3]  前闭后开
+#[::2]
+print(string[::2])
+#[1::2]
+print(string[1::2])
+#[::-1]
+print(sting[::-1])
+#[10::-3]
+print(string[10::-2])
+#[-10:-4:6]
+print(string[-10:-4:6])
+"""
+
+#题目：截取"llo w"
+string = "Hello world"
+print(string[2:7])
+print(string[2:-5])
+print(string[-10:7])
+print(string[-10:-5])
+print("string[2:7]=",string[2:7])
+print("string[2:-5]=",string[2:-5])
+print("string[-10:7]=",string[-10:7])
+print("string[-10:-5]=",string[-10:-5])
+
+
+
+

2.py

+#输入 食物名称
+input_food=input("今晚要吃什么：")
+#输出 要吃的食物
+prin("今晚我要吃_",input_food)
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