Python 如何存储熊猫数据框列表以便于访问
我有一个数据框列表Python 如何存储熊猫数据框列表以便于访问,python,list,pandas,dataframe,Python,List,Pandas,Dataframe,我有一个数据框列表 df1 = Stock Year Profit CountPercent AAPL 2012 1 38.77 AAPL 2013 1 33.33 df2 = Stock Year Profit CountPercent GOOG 2012 1 43.47 GOOG 2013 1 32.35 df3 = Stoc
df1 =
Stock Year Profit CountPercent
AAPL 2012 1 38.77
AAPL 2013 1 33.33
df2 =
Stock Year Profit CountPercent
GOOG 2012 1 43.47
GOOG 2013 1 32.35
df3 =
Stock Year Profit CountPercent
ABC 2012 1 40.00
ABC 2013 1 32.35
函数的输出是[df1,df2,df3,…
]这样的,
数据框中的所有列将相同,但行将不同
如何将这些内容存储在硬盘中,并以最快速有效的方式再次以列表的形式检索?如果列
Stock
中的值相同,您可以通过删除此列并使用dict comprehension
(键是每个df
中列Stock
的第一个值):
对于存储在磁盘中
我认为最好的方法是使用
如果每个堆栈
列中的值相同,则可以将所有df
都存储起来:
df = pd.concat([df1.set_index('Stock'), df2.set_index('Stock'), df3.set_index('Stock')])
print (df)
Year Profit CountPercent
Stock
AAPL 2012 1 38.77
AAPL 2013 1 33.33
GOOG 2012 1 43.47
GOOG 2013 1 32.35
ABC 2012 1 40.00
ABC 2013 1 32.35
store = pd.HDFStore('store.h5')
store['df'] = df
print (store)
<class 'pandas.io.pytables.HDFStore'>
File path: store.h5
/df frame (shape->[1,4])
df=pd.concat([df1.集合指数('Stock')、df2.集合指数('Stock')、df3.集合指数('Stock'))
打印(df)
年利润百分比
股票
AAPL 2012 138.77
AAPL 2013 1 33.33
GOOG 2012 143.47
GOOG 2013 132.35
ABC 2012 140.00
ABC 2013 1 32.35
store=pd.HDFStore('store.h5')
存储['df']=df
印刷品(商店)
文件路径:store.h5
/df框架(形状->[1,4])
如果Stock
列中的值相同,您可以通过删除此列并使用dict comprehension
(键是每个df
中的Stock
列的第一个值):
对于存储在磁盘中
我认为最好的方法是使用
如果每个堆栈
列中的值相同,则可以将所有df
都存储起来:
df = pd.concat([df1.set_index('Stock'), df2.set_index('Stock'), df3.set_index('Stock')])
print (df)
Year Profit CountPercent
Stock
AAPL 2012 1 38.77
AAPL 2013 1 33.33
GOOG 2012 1 43.47
GOOG 2013 1 32.35
ABC 2012 1 40.00
ABC 2013 1 32.35
store = pd.HDFStore('store.h5')
store['df'] = df
print (store)
<class 'pandas.io.pytables.HDFStore'>
File path: store.h5
/df frame (shape->[1,4])
df=pd.concat([df1.集合指数('Stock')、df2.集合指数('Stock')、df3.集合指数('Stock'))
打印(df)
年利润百分比
股票
AAPL 2012 138.77
AAPL 2013 1 33.33
GOOG 2012 143.47
GOOG 2013 132.35
ABC 2012 140.00
ABC 2013 1 32.35
store=pd.HDFStore('store.h5')
存储['df']=df
印刷品(商店)
文件路径:store.h5
/df框架(形状->[1,4])
我认为,如果您的所有DFs都具有相同的形状,那么将您的数据存储为pandas.Panel
而不是DFs列表会更自然—这就是工作原理
import io
import pandas as pd
df1 = pd.read_csv(io.StringIO("""
Stock,Year,Profit,CountPercent
AAPL,2012,1,38.77
AAPL,2013,1,33.33
"""
))
df2 = pd.read_csv(io.StringIO("""
Stock,Year,Profit,CountPercent
GOOG,2012,1,43.47
GOOG,2013,1,32.35
"""
))
df3 = pd.read_csv(io.StringIO("""
Stock,Year,Profit,CountPercent
ABC,2012,1,40.0
ABC,2013,1,32.35
"""
))
store = pd.HDFStore('c:/temp/stocks.h5')
# i had to drop `Stock` column and make it Panel-Axis, because of ERROR:
# TypeError: Cannot serialize the column [%s] because its data contents are [mixed-integer] object dtype
# when saving Panel to HDFStore ...
p = pd.Panel({df.iat[0, 0]:df.drop('Stock', 1) for df in [df1,df2,df3]})
store = pd.HDFStore('c:/temp/stocks.h5')
store.append('stocks', p, data_columns=True, mode='w')
store.close()
# read panel from HDFStore
store = pd.HDFStore('c:/temp/stocks.h5')
p = store.select('stocks')
商店:
In [18]: store
Out[18]:
<class 'pandas.io.pytables.HDFStore'>
File path: c:/temp/stocks.h5
/stocks wide_table (typ->appendable,nrows->6,ncols->3,indexers->[major_axis,minor_axis],dc->[AAPL,ABC,GOOG])
我认为,如果所有DFs都具有相同的形状,那么将数据存储为
pandas.Panel
而不是DFs列表将更为自然—这就是工作原理
import io
import pandas as pd
df1 = pd.read_csv(io.StringIO("""
Stock,Year,Profit,CountPercent
AAPL,2012,1,38.77
AAPL,2013,1,33.33
"""
))
df2 = pd.read_csv(io.StringIO("""
Stock,Year,Profit,CountPercent
GOOG,2012,1,43.47
GOOG,2013,1,32.35
"""
))
df3 = pd.read_csv(io.StringIO("""
Stock,Year,Profit,CountPercent
ABC,2012,1,40.0
ABC,2013,1,32.35
"""
))
store = pd.HDFStore('c:/temp/stocks.h5')
# i had to drop `Stock` column and make it Panel-Axis, because of ERROR:
# TypeError: Cannot serialize the column [%s] because its data contents are [mixed-integer] object dtype
# when saving Panel to HDFStore ...
p = pd.Panel({df.iat[0, 0]:df.drop('Stock', 1) for df in [df1,df2,df3]})
store = pd.HDFStore('c:/temp/stocks.h5')
store.append('stocks', p, data_columns=True, mode='w')
store.close()
# read panel from HDFStore
store = pd.HDFStore('c:/temp/stocks.h5')
p = store.select('stocks')
商店:
In [18]: store
Out[18]:
<class 'pandas.io.pytables.HDFStore'>
File path: c:/temp/stocks.h5
/stocks wide_table (typ->appendable,nrows->6,ncols->3,indexers->[major_axis,minor_axis],dc->[AAPL,ABC,GOOG])
您的所有DFs是否具有相同的形状(行和列)?您的所有DFs是否具有相同的形状(行和列)?