TypeError: 'dict_keys' object does not support indexing

[python] view plain copy

print?

1. import random  
2. outcomes = {’heads’:0, ‘tails’:0}  
3. sides = outcomes.keys()  
4. print(sides[0])  

import randomoutcomes = {'heads':0, 'tails':0}sides = outcomes.keys()print(sides[0])

会产生错误：TypeError: ‘dict_keys’ object does not support indexing

这是由于python3改变了dict.keys,返回的是dict_keys对象,支持iterable 但不支持indexable，我们可以将其明确的转化成list：

[python] view plain copy

print?

1. import random  
2. outcomes = {’heads’:0, ‘tails’:0}  
3. sides = list(outcomes.keys())  
4. print(sides[0])  # 输出tails  

import randomoutcomes = {'heads':0, 'tails':0}sides = list(outcomes.keys())print(sides[0])  # 输出tails