python中DictVectorizer的使用

from sklearn.feature_extraction import DictVectorizer
measurements = [
{'city': 'Dubai', 'temperature': 33.},
{'city': 'London', 'temperature': 12.},
{'city': 'San Fransisco', 'temperature': 18.},
]

vec = DictVectorizer()
print(vec.fit_transform(measurements).toarray())
"""
输出:
array([[  1.,   0.,   0.,  33.],
[  0.,   1.,   0.,  12.],
[  0.,   0.,   1.,  18.]])
"""
print(vec.get_feature_names())
"""
输出：
['city=Dubai', 'city=London', 'city=San Fransisco', 'temperature']
"""