python问题：IndentationError:expected an indented block错误解决

原文地址：http://hi.baidu.com/delinx/item/1789d38eafd358d05e0ec1df
   

Python语言是一款对缩进非常敏感的语言，给很多初学者带来了困惑，即便是很有经验的Python程序员，也可能陷入陷阱当中。最常见的情况是tab和空格的混用会导致错误，或者缩进不对，而这是用肉眼无法分别的。

Python uses indentation to determine when one line of code is connected to the line above it.

Python Crash Course (英文版)的page 57详细地描述了不正确的缩进所产生的错误，但是python对整个空行是不敏感的。

在编译时会出现这样的错IndentationError:expected an indented block说明此处需要缩进，你只要在出现错误的那一行，按空格或Tab（但不能混用）键缩进就行。
往往有的人会疑问：我根本就没缩进怎么还是错，不对，该缩进的地方就要缩进，不缩进反而会出错，，比如：
if xxxxxx：
（空格）xxxxx
或者
def xxxxxx：
（空格）xxxxx
还有
for xxxxxx：
（空格）xxxxx

一句话 有冒号的下一行往往要缩进，该缩进就缩进

此外python 的for 循环语句是根据缩进的情况判断for 所覆盖的范围，比如：

magicians = ['alice', 'david', 'carolina']
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")

的输出是：

Alice, that was a great trick!
I can't wait to see your next trick, Alice.


David, that was a great trick!
I can't wait to see your next trick, David.


Carolina, that was a great trick!
I can't wait to see your next trick, Carolina.

然而下面的语句，仅仅是第二个print的缩进不同

magicians = ['alice', 'david', 'carolina']
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")

其输出是

Alice, that was a great trick!
David, that was a great trick!
Carolina, that was a great trick!
I can't wait to see your next trick, Carolina.
.