我具有功能=> city
,它是分类数据,即字符串,但是不是使用replace()
进行硬编码吗?有什么聪明的方法吗?
train['city'].unique()
Output: ['city_149', 'city_83', 'city_16', 'city_64', 'city_100', 'city_21',
'city_114', 'city_103', 'city_97', 'city_160', 'city_65',
'city_90', 'city_75', 'city_136', 'city_159', 'city_67', 'city_28',
'city_10', 'city_73', 'city_76', 'city_104', 'city_27', 'city_30',
'city_61', 'city_99', 'city_41', 'city_142', 'city_9', 'city_116',
'city_128', 'city_74', 'city_69', 'city_1', 'city_176', 'city_40',
'city_123', 'city_152', 'city_165', 'city_89', 'city_36', .......]
我正在尝试什么:
train.replace(['city_149', 'city_83', 'city_16', 'city_64', 'city_100', 'city_21',
'city_114', 'city_103', 'city_97', 'city_160', 'city_65',
'city_90', 'city_75', 'city_136', 'city_159', 'city_67', 'city_28',
'city_10', 'city_73', 'city_76', 'city_104', 'city_27', 'city_30',
'city_61', 'city_99', 'city_41', 'city_142', 'city_9', 'city_116',
'city_128', 'city_74', 'city_69', 'city_1', 'city_176', 'city_40',
'city_123', 'city_152', 'city_165', 'city_89', 'city_36', .......], [1,2,3,4,5,6,7,8,9....], inplace=True)
有没有更好的方法可以将数据转换为数字?因为唯一值的数量为123
。
所以我需要对1,2,3,4,... 123中的数字进行硬编码以进行转换。提出一些更好的方法将其转换为数值。
答案 0 :(得分:4)
train['city'] = pd.factorize(train.city)[0]
train['city'] = train['city'].astype('category').cat.codes
例如:
>>> train
city
0 city_151
1 city_149
2 city_151
3 city_149
4 city_149
5 city_149
6 city_151
7 city_151
8 city_150
9 city_151
factorize
:
train['city'] = pd.factorize(train.city)[0]
>>> train
city
0 0
1 1
2 0
3 1
4 1
5 1
6 0
7 0
8 2
9 0
或astype('category')
:
train['city'] = train['city'].astype('category').cat.codes
>>> train
city
0 2
1 0
2 2
3 0
4 0
5 0
6 2
7 2
8 1
9 2
答案 1 :(得分:1)
您可以通过mapping
完成此操作:
value_mapper = dict(zip(train['city'].unique(), np.arange(1, 124)))
train['city'].map(value_mapper)
或更惯用的categorical data
:
pd.Categorical(train['city']).codes
答案 2 :(得分:1)
如果您的值始终在整数前带有下划线,则列表理解可能对您有用:
data = [int(x.split('_')[-1]) for x in train['city']]
理解会遍历x
中的每个train['city']
,将x
拆分为下划线分隔的部分,并将最后一部分转换为整数。如果您有多个下划线,例如foo_bar_5,则此方法有效。