我有以下代码,它的工作原理.这基本上重命名列中的值,以便以后可以合并它们.
pop = pd.read_csv('population.csv')
pop_recent = pop[pop['Year'] == 2014]
mapping = {
'Korea, Rep.': 'South Korea',
'Taiwan, China': 'Taiwan'
}
f= lambda x: mapping.get(x, x)
pop_recent['Country Name'] = pop_recent['Country Name'].map(f)
警告: 正在尝试在DataFrame的切片副本上设置值.尝试使用.loc [row_indexer,col_indexer] = value,请参阅文档中的警告:http: //pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy pop_recent ['国家名称'] = pop_recent ['国家名称'].地图(f)
我确实谷歌了!但似乎没有任何例子使用地图,所以我不知所措......
尝试在 Fedora 21、Python 2.7 上安装 Biopython。我做了以下
[mike@localhost Downloads](17:32)$ sudo pip2.7 install biopython
You are using pip version 6.1.1, however version 7.1.0 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Collecting biopython
/usr/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:79: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
InsecurePlatformWarning
Downloading biopython-1.65.tar.gz (12.6MB)
100% |????????????????????????????????| 12.6MB 33kB/s
Installing collected packages: biopython
Running setup.py install …我已经按照此处的建议过滤了我的数据：使用 Python 中的 Pandas，为每个组选择最高值行
author cat val
0 author1 category2 15
1 author2 category4 9
2 author3 category1 7
3 author3 category3 7
现在，我只想让作者出现在这个数据框中一次。我写了这个，但它不起作用：
def where_just_one_exists(group):
return group.loc[group.count() == 1]
most_expensive_single_category = most_expensive_for_each_model.groupby('author', as_index = False).apply(where_just_one_exists).reset_index(drop = True)
print most_expensive_single_category
错误：
File "/home/mike/anaconda/lib/python2.7/site-packages/pandas/core/indexing.py", line 1659, in check_bool_indexer
raise IndexingError('Unalignable boolean Series key provided')
pandas.core.indexing.IndexingError: Unalignable boolean Series key provided
我想要的输出是：
author cat val
0 author1 category2 15
1 author2 category4 9
2 author3 category1 7
3 author3 category3 7
使用Pandas,用于以下数据集
author1,category1,10.00
author1,category2,15.00
author1,category3,12.00
author2,category1,5.00
author2,category2,6.00
author2,category3,4.00
author2,category4,9.00
author3,category1,7.00
author3,category2,4.00
author3,category3,7.00
我想为每位作者获得最高价值
author1,category2,15.00
author2,category4,9.00
author3,category1,7.00
author3,category3,7.00
(抱歉,我是一只大熊猫.)