1. 利用for循环遍历整个列表
magicians = ['alice', 'dsvid', 'carolina'] # 遍历整个列表 for magician in magicians: print(magician)
2. 使得打印结果变得更加有实际意义
for magician in magicians: print(magician.title() + ', that was a great trick!')
运行结果:
Alice, that was a great trick!
Dsvid, that was a great trick!
Carolina, that was a great trick!
for代码行后边缩进的代码块都是循环的一部分,继续增加打印语句:
for magician in magicians: print(magician.title() + ', that was a great trick!') print("I can't wait to see your next trick, " + magician.title() + "\n")
运行结果:
![](https://img2018.cnblogs.com/blog/1713315/201906/1713315-20190613203343534-1539526925.png)
3. 对于for循环后边的属于循环模块的代码行一定要缩进。
3.1 若没有缩进:
for magician in magicians: print(magician.title() + ', that was a great trick!')
运行结果会报错:
IndentationError: expected an indented block
3.2 若有缩进的,有没有缩进的:
for magician in magicians: print(magician.title() + ', that was a great trick!') print("I can't wait to see your next trick, " + magician.title() + "\n")
程序运行不会出错,但是没有缩进的代码将在循环结束之后执行一次,只打印出有关列表最后一个元素的信息:
Alice, that was a great trick! Dsvid, that was a great trick! Carolina, that was a great trick! I can't wait to see your next trick, Carolina
3.3 若缩进了本应在循环结束之后执行的代码,则这些代码将针对每个元素循环执行一次,程序不会报错。
4. 对于for循环还要注意的一点是——for语句的末尾千万不要忘了冒号(太容易忘了,太容易忘了,太容易忘了。。。)。
一旦忘记冒号,程序运行就会报错:
SyntaxError: invalid syntax