for 循环执行缩进的语句,没有缩进的语句代码只执行一次,不会重复执行。
// manguages = ['alice','david','carolina'] for manguage in manguages: print("manguage.title()" + ", that was a great trick!") print("I can not wait to see your next trick," + "manguage.title()" + ".\n") print("Thank you everyone. That was a great magic show!")应用:可以用for循环来初始化游戏—遍历角色列表,并将每个角色打印到屏幕上。再在循环后面添加一个不缩进的代码块,在屏幕上绘制所有角色后先显示一个Play Now按钮。
打印2-10中的偶数,代码如下
//even_numbers = list(range(2,11,2)) print (even_number) //[2,4,6,8,10]将1-10的整数的平方加入到列表中,代码如下
//squares = [] for value in range(1,11): square = value**2 squares.append(square) print squares //[1,4,9,16,25,36,49,64,81,100]更简洁的代码如下
//squares = [] for value in range(1,11): squares.append(value**2) print squares //[1,4,9,16,25,36,49,64,81,100]列表解析将使代码更加简洁,同时要注意for语句末尾没有冒号
//squares = [value**2 for value in range(1,11)] print(squares)对数字进行简单的统计计算
//digits = [1,2,3,4,5,6,7,8,9,0] min(digits) max(digits) sum(digits)[:]表示遍历链表 索引从头到尾 [:4]表示遍历链表 索引从0到3 [1:]表示遍历链表 索引从1到结尾
使用语句 list_two = list_one[:]
//my_foods = ['pizza','falafel','carrot cake'] friend_foods = my_foods[:] my_foods.append('rice') my_foods.append('ice cream') print("My favorite foods are") print("my_foods") print("\nMy friend's favorite foods are") print("friend_foods")不能简单的将friend_foods = my_food,否则就得不到两个列表。
元组用圆括号(),列表用方括号[],列表的元素可改,但元组的元素不可改。若想修改元组内的元素,则
//dimensions = (10,200) for dimension in dimensions: print (dimension) dimensions = (10,400) for dimension in dimensions: print (dimension) //10 200 10 400如果要存储的数字在程序的整个周期内都不可变,则还用元组来定义。
PEP 8建议每级缩进都是用4个空格。也可使用制表符,但注意不要混合使用空格和制表符。 关于行长,每行不建议超过80字符,注释的长度不超过72字符。
1.遍历列表 for name in range[0:3] 2.列表解析使代码更简洁 squares = (value**2 for value in range[:]) 3.对列表切片并遍历 for name in names[1:3]: 4.复制列表 for name in names[:] 5.元组的遍历和修改 元组用圆括号() eg names = (‘shengnan’,‘nasong’)
