List 熊猫分组词典
熊猫新手,如果解决方案很明显的话,我很抱歉 我有一个数据帧(见下文),其中包含不同的电影场景和该电影场景的环境List 熊猫分组词典,list,pandas,dictionary,dataframe,pandas-groupby,List,Pandas,Dictionary,Dataframe,Pandas Groupby,熊猫新手,如果解决方案很明显的话,我很抱歉 我有一个数据帧(见下文),其中包含不同的电影场景和该电影场景的环境 import pandas as pd data = [{'movie' : 'movie_X', 'scene' : '1', 'environment' : 'home'}, {'movie' : 'movie_X', 'scene' : '2', 'environment' : 'car'}, {'movie' : 'movie_X', 'sc
import pandas as pd
data = [{'movie' : 'movie_X', 'scene' : '1', 'environment' : 'home'},
{'movie' : 'movie_X', 'scene' : '2', 'environment' : 'car'},
{'movie' : 'movie_X', 'scene' : '3', 'environment' : 'home'},
{'movie' : 'movie_Y', 'scene' : '1', 'environment' : 'home'},
{'movie' : 'movie_Y', 'scene' : '2', 'environment' : 'office'},
{'movie' : 'movie_Z', 'scene' : '1', 'environment' : 'boat'},
{'movie' : 'movie_Z', 'scene' : '2', 'environment' : 'beach'},
{'movie' : 'movie_Z', 'scene' : '3', 'environment' : 'home' }]
myDF = pd.DataFrame(data)
在这种情况下,电影有多种类型。我有一本字典(如下)描述每部电影属于哪种类型
genreDict = {'movie_X' : ['romance', 'action'],
'movie_Y' : ['comedy', 'romance', 'action'],
'movie_Z' : ['horror', 'thriller', 'romance']}
我想根据这本词典对myDF进行分组,特别是能够告诉特定类型中特定环境出现的次数(例如,在恐怖类型中,“船”被计数一次,“海滩”被计数一次,“家”被计数一次)。做这件事的最佳和最有效的方法是什么?我已尝试将字典映射到数据帧,然后按列表分组:
myDF['genres'] = myDF['movie'].map(genreDict)
返回:
movie scene environment genres
0 movie_X 1 home [romance, action]
1 movie_X 2 car [romance, action]
2 movie_X 3 home [romance, action]
3 movie_Y 1 home [comedy, romance, action]
4 movie_Y 2 office [comedy, romance, action]
5 movie_Z 1 boat [horror, thriller, romance]
6 movie_Z 2 beach [horror, thriller, romance]
7 movie_Z 3 home [horror, thriller, romance]
然而,我得到一个错误,说名单是不可破坏的。希望你们都能提供帮助:)非标量对象通常会导致熊猫出现问题。除此之外,您还需要整理数据,以便下一步更简单(表格结构上的主要操作通常在整理数据集上定义)。您需要一个数据集,其中不列出一行中的所有类型,而是每个类型都有自己的行 以下是实现这一目标的可能方法之一:
genre_df = pd.DataFrame(myDF['movie'].map(genreDict).tolist())
df = myDF.join(genre_df.stack().rename('genre').reset_index(level=1, drop=True))
df
Out:
environment movie scene genre
0 home movie_X 1 romance
0 home movie_X 1 action
1 car movie_X 2 romance
1 car movie_X 2 action
2 home movie_X 3 romance
2 home movie_X 3 action
3 home movie_Y 1 comedy
3 home movie_Y 1 romance
3 home movie_Y 1 action
4 office movie_Y 2 comedy
4 office movie_Y 2 romance
4 office movie_Y 2 action
5 boat movie_Z 1 horror
5 boat movie_Z 1 thriller
5 boat movie_Z 1 romance
6 beach movie_Z 2 horror
6 beach movie_Z 2 thriller
6 beach movie_Z 2 romance
7 home movie_Z 3 horror
7 home movie_Z 3 thriller
7 home movie_Z 3 romance
一旦有了这样的结构,分组或交叉制表数据就容易多了:
df.groupby('genre').size()
Out:
genre
action 5
comedy 2
horror 3
romance 8
thriller 3
dtype: int64
pd.crosstab(df['genre'], df['environment'])
Out:
environment beach boat car home office
genre
action 0 0 1 3 1
comedy 0 0 0 1 1
horror 1 1 0 1 0
romance 1 1 1 4 1
thriller 1 1 0 1 0
哈德利·威克姆(Hadley Wickham)有一篇很棒的读物:。非标量对象通常会导致熊猫出现问题。除此之外,您还需要整理数据,以便下一步更简单(表格结构上的主要操作通常在整理数据集上定义)。您需要一个数据集,其中不列出一行中的所有类型,而是每个类型都有自己的行 以下是实现这一目标的可能方法之一:
genre_df = pd.DataFrame(myDF['movie'].map(genreDict).tolist())
df = myDF.join(genre_df.stack().rename('genre').reset_index(level=1, drop=True))
df
Out:
environment movie scene genre
0 home movie_X 1 romance
0 home movie_X 1 action
1 car movie_X 2 romance
1 car movie_X 2 action
2 home movie_X 3 romance
2 home movie_X 3 action
3 home movie_Y 1 comedy
3 home movie_Y 1 romance
3 home movie_Y 1 action
4 office movie_Y 2 comedy
4 office movie_Y 2 romance
4 office movie_Y 2 action
5 boat movie_Z 1 horror
5 boat movie_Z 1 thriller
5 boat movie_Z 1 romance
6 beach movie_Z 2 horror
6 beach movie_Z 2 thriller
6 beach movie_Z 2 romance
7 home movie_Z 3 horror
7 home movie_Z 3 thriller
7 home movie_Z 3 romance
一旦有了这样的结构,分组或交叉制表数据就容易多了:
df.groupby('genre').size()
Out:
genre
action 5
comedy 2
horror 3
romance 8
thriller 3
dtype: int64
pd.crosstab(df['genre'], df['environment'])
Out:
environment beach boat car home office
genre
action 0 0 1 3 1
comedy 0 0 0 1 1
horror 1 1 0 1 0
romance 1 1 1 4 1
thriller 1 1 0 1 0
Hadley Wickham阅读了一篇很棒的文章:.如果数据帧越大,则使用
numpy
重复行,通过列表
和:
然后使用并聚合:
如果数据帧越大,则使用
numpy
按列表
重复行,并且:
然后使用并聚合:
你能发布你想要的数据集吗?你能发布你想要的数据集吗?